Solved: Estradiol is a female sexual hormone that causes

Problem 72 Limiting Reactants (Section) (a) Define the terms theoretical yield, actual yield, and percent yield, (b) Why is the actual yield in a reaction almost always less than the theoretical yield? (c) Can a reaction ever have 110% actual yield?

Calculate the mass percent composition of carbon in each carbon-containing compound. a. CH4 b. C2H6 c. C2H2 d. C2H5Cl

Iron in the earth is in the form of iron ore. Common ores include Fe2O3 (hematite), Fe3O4 (magnetite), and FeCO3 (siderite). Calculate the mass percent composition of iron for each of these iron ores. Which ore has the highest iron content?

Problem 75 Limiting Reactants (Section) Consider the mixture of ethanol, C2H5OH, and 0I shown in the accompanying diagram.: (a) Write a balanced equation for the combustion reaction that occurs between ethanol and oxygen (b) Which reactant is the limiting reactant? (c) How many molecules of C02, H20, C2H50H, and 02 will be present if the reaction goes to completion?

Problem 77 Limiting Reactants (Section) Sodium hydroxide reacts with carbon dioxide as follows: Which is the limiting reactant when 1.85 mol NaOH and 1.00 mol CO2 are allowed to react? How many moles of Na2CO3 can be produced? How many moles of the excess reactant remain after the completion of the reaction?

Problem 78 Limiting Reactants (Section) Aluminum hydroxide reacts with sulfuric acid as follows: Which is the limiting reactant when 0.500 mol AI(OH)3 and 0.500 mol H2SO4 are allowed to react? How many moles of AI2(SO4)3 can form under these conditions? How many moles of the excess reactant remain after the completion of the reaction?

Write a ratio showing the relationship between the molar amounts of each element for each compound. (See Appendix IIA for color codes.)

Problem 80 Limiting Reactants (Section) One of the steps in the commercial process for converting ammonia to nitric acid is the conversion of NH3 to NO: In a certain experiment, 2.00 g of NH3 reacts with 2.50 g of O2.: (a) Which is the limiting reactant? (b) How many grams of NO and H2O form? (c) How many grams of the excess reactant remain after the limiting reactant is completely consumed? (d) Show that your calculations in parts (b) and (c) are consistent with the law of conservation of mass.

Problem 81 Limiting Reactants (Section) Solutions of sodium carbonate and silver nitrate react to form solid silver carbonate and a solution of sodium nitrate. A solution containing 3.50 g of sodium carbonate is mixed with one containing 5.00 g of silver nitrate. How many grams of sodium carbonate, silver nitrate, silver carbonate, and sodium nitrate are present after the reaction is complete?

Problem 82 Limiting Reactants (Section) Solutions of sulfuric acid and lead(ll) acetate react to form solid lead(ll) sulfate and a solution of acetic acid. If 5.00 g of sulfuric acid and 5.00 g of lead(ll) acetate are mixed, calculate the number of grams of sulfuric acid, lead(ll) acetate, lead(ll) sulfate, and acetic acid present in the mixture after the reaction is complete.

Problem 83. Limiting Reactants (Section) When benzene (C6H6) reacts with bromine (Br2), bromobenzene (C6H5Br) is obtained: (a) When 30.0 g of benzene reacts with 65.0 g of bromine, what is the theoretical yield of bromobenzene?; (b) If the actual yield of bromobenzene is 42.3 g, what is the percentage yield?

Problem 84 Limiting Reactants (Section) When ethane (C2H6) reacts with chlorine (CI2), the main product is C2H5CI, but other products containing Cl, such as C2H4CI2, are also obtained in small quantities. The formation of these other products reduces the yield of C2H5CI.: (a) Calculate the theoretical yield of C2H5CI when 125 g of C2H6 reacts with 255 g of CI2, assuming that C2H6 and CI2 react only to form C2H2CI and HCL; (b) Calculate the percent yield of C2H5CI if the reaction produces 206 g of C2H5CI.

Problem 86 Limiting Reactants (Section) When hydrogen sulfide gas is bubbled into a solution of sodium hydroxide, the reaction forms sodium sulfide and water. How many grams of sodium sulfide are formed if 1.25 g of hydrogen sulfide is bubbled into a solution containing 2.00 g of sodium hydroxide, assuming that the sodium sulfide is made in 92.0% yield?

Problem 87 Write the balanced chemical equations for (a) the complete combustion of acetic acid (CH3COOH), the main active ingredient in vinegar; (b) the decomposition of solid calcium hydroxide into solid calcium (II) oxide (lime) and water vapor; (c) the combination reaction between nickel metal and chlorine gas.

Problem 85 Limiting Reactants (Section) Hydrogen sulfide is an impurity in natural gas that must be removed. One common removal method is called the Claus process, which relies on the reaction: 8 H2S(g) + 4 O2(gHS8(/) + 8 H2O(g) Under optimal conditions the Claus process gives 98% yield of S8 from H2S. If you started with 30.0 grams of H2S and 50.0 grams of 02, how many grams of S8 would be produced, assuming 98% yield?

Problem 88 If 1.5 mol C2H5OH, 1.5 mol C3H8, and 1.5 mol CH3CH2COCH3 are completely combusted oxygen, which produces the largest number of moles of H20? Which produces the least? Explain.

Problem 89 The effectiveness of nitrogen fertilizers depends on both their ability to deliver nitrogen to plants and the amount of nitrogen they can deliver. Four common nitrogen-containing fertilizers are ammonia, ammonium nitrate, ammonium sulfate, and urea [(NH2)2CO]. Rank these fertilizers in terms of the mass percentage nitrogen they contain. Step-by-step solution Stem1

Problem 90 (a) The molecular formula of acetylsalicylic acid (aspirin), one of the most common pain relievers, is C9H8O4. How many moles of C9H8O4 are in a 0.500-g tablet of aspirin? (b) How many molecules of C9H8O4 are in this tablet? (c) How many carbon atoms are in the tablet?

Problem 92 (a) One molecule of the antibiotic penicillin G has a mass of 5.342 x 10-21 g. What is the molar mass of penicillin G? (b) Hemoglobin, the oxygen-carrying protein in red blood cells, has four iron atoms per molecule and contains 0.340% iron by mass. Calculate the molar mass of hemoglobin.

Problem 94 The koala dines exclusively on eucalyptus leaves. Its digestive system detoxifies the eucalyptus oil, a poison to other animals. The chief constituent in eucalyptus oil is a substance called eucalyptol, which contains 77.87% C, 11.76% H, and the remainder 0.: (a) What is the empirical formula for this substance? (b) A mass spectrum of eucalyptol shows a peak at about 154 amu. What is the molecular formula of the substance?

Problem 93 Serotonin is a compound that conducts nerve impulses in the brain. It contains 68.2 mass percent C, 6.86 mass percent H, 15.9 mass percent N, and 9.08 mass percent 0. Its molar mass is 176 g/mol. Determine its molecular formula.

Problem 91 Very small crystals composed of 1000 to 100,000 atoms, called quantum dots, are being investigated for use in electronic devices. (a) A quantum dot was made of solid silicon in the shape of a sphere, with a diameter of 4 nm. Calculate the mass of the quantum dot, using the density of silicon (2.3 g/cm3). (b) How many silicon atoms are in the quantum dot? (c) The density of germanium is 5.325 g/cm3. If you made a 4-nm quantum dot of germanium, how many Ge atoms would it contain? Assume the dot is spherical.

Problem 96 An organic compound was found to contain only C, H, and Cl. When a 1.50-g sample of the compound was completely combusted in air, 3.52 g of CO2 was formed. In a separate experiment the chlorine in a 1.00-g sample of the compound was converted to 1.27 g of AgCI. Determine the empirical formula of the compound.

Problem 97 A compound, KBrOx, where x is unknown, is analyzed and found to contain 52.92% Br. What is the value of x?

Problem 98 An element X forms an iodide (XI3) and a chloride (XCI 3). The iodide is quantitatively converted to the chloride when it is heated in a stream of chlorine: 2 XI3 + 3 CI2—>2 XCI3 + 3 l2 If 0.5000 g of XI3 is treated, 0.2360 g of XCI 3 is obtained.; (a) Calculate the atomic weight of the element X.; (b) Identify the element X.

Problem 99 A method used by the U S. Environmental Protection Agency (EPA) for determining the concentration of ozone in air is to pass the air sample through a 'bubbler5 containing sodium iodide, which removes the ozone according to the following equation: (a) How many moles of sodium iodide are needed to remove 5.95 * 10-6 mol of O3?; (b) How many grams of sodium iodide are needed to remove 1.3 mg of O3?

Problem 100 A chemical plant uses electrical energy to decompose aqueous solutions of NaCI to give CI2, H2, and NaOH: If the plant produces 1.5 * 106 kg (1500 metric tons) of CI2 daily, estimate the quantities of H2 and NaOH produced.

Problem 101 The fat stored in a camel's hump is a source of both energy and water. Calculate the mass of H20 produced by the metabolism of 1.0 kg of fat, assuming the fat consists entirely of tristearin (?C57H110O6?), a typical animal fat, and assuming that during metabolism, tristearin reacts with O2 to form only CO2 and H2O.

Problem 102 When hydrocarbons are burned in a limited amount of air, both CO and CO2 form. When 0.450 g of a particular hydrocarbon was burned in air, 0.467 g of CO, 0.733 g of CO2, and 0.450 g of H2O were formed.: (a) What is the empirical formula of the compound? (b) How many grams of O2 were used in the reaction? (c) How many grams would have been required for complete combustion?

A mixture of \(N_2\)(g) and \(H_2\) reacts in a closed container to form ammonia, \(NH_3\)(g). The reaction ceases before either reactant has been totally consumed. At this stage 3.0 mol \(N_2\) , 3.0 mol \(H_2\), and 3.0 mol \(NH_3\) are present. How many moles of \(N_2\) and \(H_2\) were present originally? Text Transcriptions: N_2 H_2 NH_3

Problem 105 When a mixture of 10.0 g of acetylene (C2H2) and 10.0 g of oxygen (O2) is ignited, the resultant combustion reaction produces CO2 and H2O.: (a) Write the balanced chemical equation for this reaction, (b) Which is the limiting reactant? (c) How many grams of C2H2, O2, CO2, and H=O are present after the reaction is complete?

Problem 106 Consider a sample of calcium carbonate in the form of a cube measuring 2.005 in. on each edge. If the sample has a density of 2.71 g/cm3, how many oxygen atoms does it contain?

Problem 107 You are given a cube of silver metal that measures 1.000 cm on each edge. The density of silver is 10.5 g/cm3. How many atoms are in this cube? (b) Because atoms are spherical, they cannot occupy all of the space of the cube. The silver atoms pack in the solid in such a way that 74% of the volume of the solid is actually filled with the silver atoms. Calculate the volume of a single silver atom, (c) Using the volume of a silver atom and the formula for the volume of a sphere, calculate the radius in angstroms of a silver atom.

Problem 109 Structural isomerism, with 1-propanol and 2-propanol as examples. Determine which of these properties would distinguish these two substances: (a) boiling point, (b) combustion analysis results, (c) molecular weight, (d) density at a given temperature and pressure.

Problem 111 Hydrogen cyanide, HCN, is a poisonous gas. The lethal dose is approximately 300 mg HCN per kilogram of air when inhaled.: (a) Calculate the amount of HCN that gives the lethal dose in a small laboratory room measuring 12 * 15 * 8.0 ft. The density of air at 26 °C is 0.00118 g/cm3. (b) If the HCN is formed by reaction of NaCN with an acid such as H2S04, what mass of NaCN gives the lethal dose in the room? 2 NaCN(s) + H2SO4(agHNa2SO4(ag) + 2 HCN(g) (c) HCN forms when synthetic fibers containing Orion® or Acrilan® burn. Acrilan® has an empirical formula of CH2CHCN, so HCN is 50.9% of the formula by mass. A rug measures 12 x 15 ft and contains 30 oz of Acrilan® fibers per square yard of carpet. If the rug burns, will a lethal dose of HCN be generated in the room? Assume that the yield of HCN from the fibers is 20% and that the carpet is 50% ?consumed.

Problem 112 The source of oxygen that drives the internal combustion engine in an automobile is air. Air is a mixture of gases, principally N2(~79%) and O2(~20%). In the cylinder of an automobile engine, nitrogen can react with oxygen to produce nitric oxide gas, NO. As NO is emitted from the tailpipe of the car, it can react with more oxygen to produce nitrogen dioxide gas. (a) Write balanced chemical equations for both reactions, (b) Both nitric oxide and nitrogen dioxide are pollutants that can lead to acid rain and global warming; collectively, they are called ‘NOx' gases. In 2007, the United States emitted an estimated 22 million tons of nitrogen dioxide into the atmosphere. How many grams of nitrogen dioxide is this? (c) The production of NOx gases is an unwanted side reaction of the main engine combustion process that turns octane, C8H18, into C02 and water. If 85% of the oxygen in an engine is used to combust octane and the remainder used to produce nitrogen dioxide, calculate how many grams of nitrogen dioxide would be produced during the combustion of 500 g of octane.

Problem 65 Quantitative Information from Balanced Equations (Section) Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulphide: (a) Write the balanced chemical equation for this reaction (b) How many grams of aluminum hydroxide are obtained from 14.2 g of aluminum sulfide?

Problem 110 A particular coal contains 2.5% sulfur by mass. When this coal is burned at a power plant, the sulfur is converted into sulfur dioxide gas, which is a pollutant. To reduce sulfur dioxide emissions, calcium oxide (lime) is used. The sulfur dioxide reacts with calcium oxide to form solid calcium sulfite.: (a) Write the balanced chemical equation for the reaction., (b) If the coal is burned in a power plant that uses 2000 tons of coal per day, what mass of calcium oxide is required daily to eliminate the sulfur dioxide?, (c) How many grams of calcium sulfite are produced daily by this power plant?

Problem 68 Quantitative Information from Balanced Equations (Section) The complete combustion of octane, C8H18, a component of gasoline, proceeds as follows: 2 C8H18(/) + 25 O2(g)—»16 C2(g) + 18 H2O(g) (a) How many moles of O2 are needed to burn 1.50 mol of C8H18? (b) How many grams of O2 are needed to burn 10.0 g of C8H18? (c) Octane has a density of 0.692 g/ml at 20 °C. How many grams of 02 are required to burn 15.0 gal of C8H18 (the capacity of an average fuel tank)? (d) How many grams of CO2 are produced when 15.0 gal of C8H18 are combusted?

A sugar crystal contains approximately 1.8 x 1017 sucrose (C12H22O11) molecules. What is its mass in mg?

What is the mass in grams of a single atom of each of the following elements? (a) As, (b) Ni

What is the mass in grams of 1.00 3 1012 lead (Pb) atoms?

A modern penny weighs 2.5 g but contains only 0.063 g of copper (Cu). How many copper atoms are present in a modern penny

Which of the following has more atoms: 1.10 g of hydrogen atoms or 14.7 g of chromium atoms?

Which of the following has a greater mass: 2 atoms of lead or 5.1 3 10223 mole of helium.

Calculate the molecular mass or formula mass (in amu) of each of the following substances: (a) CH4, (b) NO2, (c) SO3, (d) C6H6, (e) NaI, (f) K2SO4, (g) Ca3(PO4)2.

Calculate the molar mass of the following substances: (a) Li2CO3, (b) CS2, (c) CHCl3 (chloroform), (d) C6H8O6 (ascorbic acid, or vitamin C), (e) KNO3, (f) Mg3N2.

Calculate the molar mass of a compound if 0.372 mole of it has a mass of 152 g

How many molecules of ethane (C2H6) are present in 0.334 g of C2H6?

Calculate the number of C, H, and O atoms in 1.50 g of glucose (C6H12O6), a sugar.

Dimethyl sulfoxide [(CH3)2SO], also called DMSO, is an important solvent that penetrates the skin, enabling it to be used as a topical drug-delivery agent. Calculate the number of C, S, H, and O atoms in 7.14 3 103 g of dimethyl sulfoxide

Pheromones are a special type of compound secreted by the females of many insect species to attract the males for mating. One pheromone has the molecular formula C19H38O. Normally, the amount of this pheromone secreted by a female insect is about 1.0 3 10212 g. How many molecules are there in this quantity?

The density of water is 1.00 g/mL at 48C. How many water molecules are present in 2.56 mL of water at this temperature?

Describe the operation of a mass spectrometer

Describe how you would determine the isotopic abundance of an element from its mass spectrum.

Carbon has two stable isotopes, 12 6C and 13 6C, and fluorine has only one stable isotope, 19 9F. How many peaks would you observe in the mass spectrum of the positive ion of CF1 4? Assume that the ion does not break up into smaller fragments

Hydrogen has two stable isotopes, 1 1H and 2 1H, and sulfur has four stable isotopes, 32 16S, 33 16S, 34 16S, and 36 16S. How many peaks would you observe in the mass spectrum of the positive ion of hydrogen sulfide, H2S1? Assume no decomposition of the ion into smaller fragments.

Use ammonia (NH3) to explain what is meant by the percent composition by mass of a compound.

Describe how the knowledge of the percent composition by mass of an unknown compound can help us identify the compound.

What does the word empirical in empirical formula mean?

If we know the empirical formula of a compound, what additional information do we need to determine its molecular formula?

Tin (Sn) exists in Earths crust as SnO2. Calculate the percent composition by mass of Sn and O in SnO2.

For many years chloroform (CHCl3) was used as an inhalation anesthetic in spite of the fact that it is also a toxic substance that may cause severe liver, kidney, and heart damage. Calculate the percent composition by mass of this compound.

Cinnamic alcohol is used mainly in perfumery, particularly in soaps and cosmetics. Its molecular formula is C9H10O. (a) Calculate the percent composition by mass of C, H, and O in cinnamic alcohol. (b) How many molecules of cinnamic alcohol are contained in a sample of mass 0.469 g?

All of the substances listed here are fertilizers that contribute nitrogen to the soil. Which of these is the richest source of nitrogen on a mass percentage basis? (a) Urea, (NH2)2CO (b) Ammonium nitrate, NH4NO3 (c) Guanidine, HNC(NH2)2 (d) Ammonia, NH3

Allicin is the compound responsible for the characteristic smell of garlic. An analysis of the compound gives the following percent composition by mass: C: 44.4 percent; H: 6.21 percent; S: 39.5 percent; O: 9.86 percent. Calculate its empirical formula. What is its molecular formula given that its molar mass is about 162 g?

Peroxyacylnitrate (PAN) is one of the components of smog. It is a compound of C, H, N, and O. Determine the percent composition of oxygen and the empirical formula from the following percent composition by mass: 19.8 percent C, 2.50 percent H, 11.6 percent N. What is its molecular formula given that its molar mass is about 120 g?

The formula for rust can be represented by Fe2O3. How many moles of Fe are present in 24.6 g of the compound?

How many grams of sulfur (S) are needed to react completely with 246 g of mercury (Hg) to form HgS?

Calculate the mass in grams of iodine (I2) that will react completely with 20.4 g of aluminum (Al) to form aluminum iodide (AlI3).

Tin(II) fluoride (SnF2) is often added to toothpaste as an ingredient to prevent tooth decay. What is the mass of F in grams in 24.6 g of the compound?

What are the empirical formulas of the compounds with the following compositions? (a) 2.1 percent H, 65.3 percent O, 32.6 percent S, (b) 20.2 percent Al, 79.8 percent Cl.

What are the empirical formulas of the compounds with the following compositions? (a) 40.1 percent C, 6.6 percent H, 53.3 percent O, (b) 18.4 percent C, 21.5 percent N, 60.1 percent K

The anticaking agent added to Morton salt is calcium silicate, CaSiO3. This compound can absorb up to 2.5 times its mass of water and still remains a free-flowing powder. Calculate the percent composition of CaSiO3.

The empirical formula of a compound is CH. If the molar mass of this compound is about 78 g, what is its molecular formula?

The molar mass of caffeine is 194.19 g. Is the molecular formula of caffeine C4H5N2O or C8H10N4O2?

Monosodium glutamate (MSG), a food-flavor enhancer, has been blamed for Chinese restaurant syndrome, the symptoms of which are headaches and chest pains. MSG has the following composition by mass: 35.51 percent C, 4.77 percent H, 37.85 percent O, 8.29 percent N, and 13.60 percent Na. What is its molecular formula if its molar mass is about 169 g?

Use the formation of water from hydrogen and oxygen to explain the following terms: chemical reaction, reactant, product.

What is the difference between a chemical reaction and a chemical equation?

Why must a chemical equation be balanced? What law is obeyed by a balanced chemical equation?

Write the symbols used to represent gas, liquid, solid, and the aqueous phase in chemical equations.

Balance the following equations using the method outlined in Section 3.7: (a) C 1 O2 CO (b) CO 1 O2 CO2 (c) H2 1 Br2 HBr (d) K 1 H2O KOH 1 H2 (e) Mg 1 O2 MgO (f) O3 O2 (g) H2O2 H2O 1 O2 (h) N2 1 H2 NH3 (i) Zn 1 AgCl ZnCl2 1 Ag (j) S8 1 O2 SO2 (k) NaOH 1 H2SO4 Na2SO4 1 H2O (l) Cl2 1 NaI NaCl 1 I2 (m) KOH 1 H3PO4 K3PO4 1 H2O (n) CH4 1 Br2 CBr4 1 HBr

Balance the following equations using the method outlined in Section 3.7: (a) N2O5 N2O4 1 O2 (b) KNO3 KNO2 1 O2 (c) NH4NO3 N2O 1 H2O (d) NH4NO2 N2 1 H2O (e) NaHCO3 Na2CO3 1 H2O 1 CO2 (f) P4O10 1 H2O H3PO4 (g) HCl 1 CaCO3 CaCl2 1 H2O 1 CO2 (h) Al 1 H2SO4 Al2(SO4)3 1 H2 (i) CO2 1 KOH K2CO3 1 H2O (j) CH4 1 O2 CO2 1 H2O (k) Be2C 1 H2O Be(OH)2 1 CH4 (l) Cu 1 HNO3 Cu(NO3)2 1 NO 1 H2O (m) S 1 HNO3 H2SO4 1 NO2 1 H2O (n) NH3 1 CuO Cu 1 N2 1 H2O

On what law is stoichiometry based? Why is it essential to use balanced equations in solving stoichiometric problems?

Describe the steps involved in the mole method.

Which of the following equations best represents the reaction shown in the diagram? (a) 8A 1 4B C 1 D (b) 4A 1 8B 4C 1 4D (c) 2A 1 B C 1 D (d) 4A 1 2B 4C 1 4D (e) 2A 1 4B C 1 D A D C B

Which of the following equations best represents the reaction shown in the diagram? (a) A 1 B C 1 D (b) 6A 1 4B C 1 D (c) A 1 2B 2C 1 D (d) 3A 1 2B 2C 1 D (e) 3A 1 2B 4C 1 2D 8n A D C B

Consider the combustion of carbon monoxide (CO) in oxygen gas: 2CO(g) 1 O2(g) 2CO2(g) Starting with 3.60 moles of CO, calculate the number of moles of CO2 produced if there is enough oxygen gas to react with all of the CO.

Silicon tetrachloride (SiCl4) can be prepared by heating Si in chlorine gas: Si(s) 1 2Cl2(g) SiCl4(l) In one reaction, 0.507 mole of SiCl4 is produced. How many moles of molecular chlorine were used in the reaction?

Ammonia is a principal nitrogen fertilizer. It is prepared by the reaction between hydrogen and nitrogen. 3H2(g) 1 N2(g) 2NH3(g) In a particular reaction, 6.0 moles of NH3 were produced. How many moles of H2 and how many moles of N2 were reacted to produce this amount of NH3?

Certain race cars use methanol (CH3OH, also called wood alcohol) as a fuel. The combustion of methanol occurs according to the following equation: 2CH3OH(l) 1 3O2(g) 2CO2(g) 1 4H2O(l) In a particular reaction, 9.8 moles of CH3OH are reacted with an excess of O2. Calculate the number of moles of H2O formed.

The annual production of sulfur dioxide from burning coal and fossil fuels, auto exhaust, and other sources is about 26 million tons. The equation for the reaction is S(s) 1 O2(g) SO2(g) How much sulfur (in tons), present in the original materials, would result in that quantity of SO2?

When baking soda (sodium bicarbonate or sodium hydrogen carbonate, NaHCO3) is heated, it releases carbon dioxide gas, which is responsible for the rising of cookies, donuts, and bread. (a) Write a balanced equation for the decomposition of the compound (one of the products is Na2CO3). (b) Calculate the mass of NaHCO3 required to produce 20.5 g of CO2

If chlorine bleach is mixed with other cleaning products containing ammonia, the toxic gas NCl3(g) can form according to the equation: 3NaClO(aq) 1 NH3(aq) 3NaOH(aq) 1 NCl3(g) When 2.94 g of NH3 reacts with an excess of NaClO according to the preceding reaction, how many grams of NCl3 are formed?

Fermentation is a complex chemical process of wine making in which glucose is converted into ethanol and carbon dioxide: C6H12O6 2C2H5OH 1 2CO2 glucose ethanol Starting with 500.4 g of glucose, what is the maximum amount of ethanol in grams and in liters that can be obtained by this process? (Density of ethanol 5 0.789 g/mL.)

Each copper(II) sulfate unit is associated with five water molecules in crystalline copper(II) sulfate pentahydrate (CuSO4 ? 5H2O). When this compound is heated in air above 1008C, it loses the water molecules and also its blue color: CuSO4 ? 5H2O CuSO4 1 5H2O If 9.60 g of CuSO4 are left after heating 15.01 g of the blue compound, calculate the number of moles of H2O originally present in the compound.

For many years the recovery of goldthat is, the separation of gold from other materialsinvolved the use of potassium cyanide: 4Au 1 8KCN 1 O2 1 2H2O 4KAu(CN)2 1 4KOH What is the minimum amount of KCN in moles needed to extract 29.0 g (about an ounce) of gold?

Limestone (CaCO3) is decomposed by heating to quicklime (CaO) and carbon dioxide. Calculate how many grams of quicklime can be produced from 1.0 kg of limestone.

Nitrous oxide (N2O) is also called laughing gas. It can be prepared by the thermal decomposition of ammonium nitrate (NH4NO3). The other product is H2O. (a) Write a balanced equation for this reaction. (b) How many grams of N2O are formed if 0.46 mole of NH4NO3 is used in the reaction?

The fertilizer ammonium sulfate [(NH4)2SO4] is prepared by the reaction between ammonia (NH3) and sulfuric acid: 2NH3(g) 1 H2SO4(aq) (NH4)2SO4(aq) How many kilograms of NH3 are needed to produce 1.00 3 105 kg of (NH4)2SO4?

A common laboratory preparation of oxygen gas is the thermal decomposition of potassium chlorate (KClO3). Assuming complete decomposition, calculate the number of grams of O2 gas that can be obtained from 46.0 g of KClO3. (The products are KCl and O2.)

Define limiting reagent and excess reagent. What is the significance of the limiting reagent in predicting the amount of the product obtained in a reaction? Can there be a limiting reagent if only one reactant is present?

Give an everyday example that illustrates the limiting reagent concept.

Consider the reaction 2A 1 B C (a) In the diagram here that represents the reaction, which reactant, A or B, is the limiting reagent? (b) Assuming complete reaction, draw a molecularmodel representation of the amounts of reactants and products left after the reaction. The atomic arrangement in C is ABA. A B

Consider the reaction N2 1 3H2 2NH3 Assuming each model represents 1 mole of the substance, show the number of moles of the product and the excess reagent left after the complete reaction. H2 N2 NH3

Nitric oxide (NO) reacts with oxygen gas to form nitrogen dioxide (NO2), a dark-brown gas: 2NO(g) 1 O2(g) 2NO2(g) In one experiment 0.886 mole of NO is mixed with 0.503 mole of O2. Calculate which of the two reactants is the limiting reagent. Calculate also the number of moles of NO2 produced.

Ammonia and sulfuric acid react to form ammonium sulfate. (a) Write an equation for the reaction. (b) Determine the starting mass (in g) of each reactant if 20.3 g of ammonium sulfate is produced and 5.89 g of sulfuric acid remains unreacted

Propane (C3H8) is a component of natural gas and is used in domestic cooking and heating. (a) Balance the following equation representing the combustion of propane in air: C3H8 1 O2 CO2 1 H2O (b) How many grams of carbon dioxide can be produced by burning 3.65 moles of propane? Assume that oxygen is the excess reagent in this reaction

Consider the reaction MnO2 1 4HCl MnCl2 1 Cl2 1 2H2O If 0.86 mole of MnO2 and 48.2 g of HCl react, which reagent will be used up first? How many grams of Cl2 will be produced?

Why is the theoretical yield of a reaction determined only by the amount of the limiting reagent?

Why is the actual yield of a reaction almost always smaller than the theoretical yield?

Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of aluminum metal. It is prepared by the reaction CaF2 1 H2SO4 CaSO4 1 2HF In one process, 6.00 kg of CaF2 are treated with an excess of H2SO4 and yield 2.86 kg of HF. Calculate the percent yield of HF.

Nitroglycerin (C3H5N3O9) is a powerful explosive. Its decomposition may be represented by 4C3H5N3O9 6N2 1 12CO2 1 10H2O 1 O2 This reaction generates a large amount of heat and many gaseous products. It is the sudden formation of these gases, together with their rapid expansion, that produces the explosion. (a) What is the maximum amount of O2 in grams that can be obtained from 2.00 3 102 g of nitroglycerin? (b) Calculate the percent yield in this reaction if the amount of O2 generated is found to be 6.55 g.

Titanium(IV) oxide (TiO2) is a white substance produced by the action of sulfuric acid on the mineral ilmenite (FeTiO3): FeTiO3 1 H2SO4 TiO2 1 FeSO4 1 H2O Its opaque and nontoxic properties make it suitable as a pigment in plastics and paints. In one process, 8.00 3 103 kg of FeTiO3 yielded 3.67 3 103 kg of TiO2. What is the percent yield of the reaction?

Ethylene (C2H4), an important industrial organic chemical, can be prepared by heating hexane (C6H14) at 8008C: C6H14 C2H4 1 other products If the yield of ethylene production is 42.5 percent, what mass of hexane must be reacted to produce 481 g of ethylene?

When heated, lithium reacts with nitrogen to form lithium nitride: 6Li(s) 1 N2(g) 2Li3N(s) What is the theoretical yield of Li3N in grams when 12.3 g of Li are heated with 33.6 g of N2? If the actual yield of Li3N is 5.89 g, what is the percent yield of the reaction?

Disulfide dichloride (S2Cl2) is used in the vulcanization of rubber, a process that prevents the slippage of rubber molecules past one another when stretched. It is prepared by heating sulfur in an atmosphere of chlorine: S8(l) 1 4Cl2(g) 4S2Cl2(l) What is the theoretical yield of S2Cl2 in grams when 4.06 g of S8 are heated with 6.24 g of Cl2? If the actual yield of S2Cl2 is 6.55 g, what is the percent yield?

Gallium is an important element in the production of semiconductors. The average atomic mass of 69 31Ga (68.9256 amu) and 71 31Ga (70.9247 amu) is 69.72 amu. Calculate the natural abundances of the gallium isotopes.

Rubidium is used in atomic clocks and other precise electronic equipment. The average atomic mass of 85 37Rb (84.912 amu) and 87 37Rb (86.909 amu) is 85.47 amu. Calculate the natural abundances of the rubidium isotopes

The following diagram represents the products (CO2 and H2O) formed after the combustion of a hydrocarbon (a compound containing only C and H atoms). Write an equation for the reaction. (Hint: The molar mass of the hydrocarbon is about 30 g.) CO2 H2O

Consider the reaction of hydrogen gas with oxygen gas: 2H2(g) 1 O2(g) 2H2O(g) H2 O2 H2O Assuming complete reaction, which of the diagrams shown next represents the amounts of reactants and products left after the reaction? (a) (b) (c) (d)

Ethylene reacts with hydrogen chloride to form ethyl chloride: C2H4(g) 1 HCl(g) C2H5Cl(g) Calculate the mass of ethyl chloride formed if 4.66 g of ethylene reacts with an 89.4 percent yield

Write balanced equations for the following reactions described in words. (a) Pentane burns in oxygen to form carbon dioxide and water. (b) Sodium bicarbonate reacts with hydrochloric acid to form carbon dioxide, sodium chloride, and water. (c) When heated in an atmosphere of nitrogen, lithium forms lithium nitride. (d) Phosphorus trichloride reacts with water to form phosphorus acid and hydrogen chloride. (e) Copper(II) oxide heated with ammonia will form copper, nitrogen gas, and water.

Industrially, nitric acid is produced by the Ostwald process represented by the following equations: 4NH3(g) 1 5O2(g) 4NO(g) 1 6H2O(l) 2NO(g) 1 O2(g) 2NO2(g) 2NO2(g) 1 H2O(l) HNO3(aq) 1 HNO2(aq) What mass of NH3 (in g) must be used to produce 1.00 ton of HNO3 by the above procedure, assuming an 80 percent yield in each step? (1 ton 5 2000 lb; 1 lb 5 453.6 g.)

A sample of a compound of Cl and O reacts with an excess of H2 to give 0.233 g of HCl and 0.403 g of H2O. Determine the empirical formula of the compound.

How many grams of H2O will be produced from the complete combustion of 26.7 g of butane (C4H10)?

A 26.2-g sample of oxalic acid hydrate (H2C2O4 ? 2H2O) is heated in an oven until all the water is driven off. How much of the anhydrous acid is left?

The atomic mass of element X is 33.42 amu. A 27.22-g sample of X combines with 84.10 g of another element Y to form a compound XY. Calculate the atomic mass of Y

How many moles of O are needed to combine with 0.212 mole of C to form (a) CO and (b) CO2?

A research chemist used a mass spectrometer to study the two isotopes of an element. Over time, she recorded a number of mass spectra of these isotopes. On analysis, she noticed that the ratio of the taller peak (the more abundant isotope) to the shorter peak (the less abundant isotope) gradually increased with time. Assuming that the mass spectrometer was functioning normally, what do you think was causing this change?

The aluminum sulfate hydrate [Al2(SO4)3 ? xH2O] contains 8.10 percent Al by mass. Calculate x, that is, the number of water molecules associated with each Al2(SO4)3 unit.

The explosive nitroglycerin (C3H5N3O9) has also been used as a drug to treat heart patients to relieve pain (angina pectoris). We now know that nitroglycerin produces nitric oxide (NO), which causes muscles to relax and allows the arteries to dilate. If each nitroglycerin molecule releases one NO per atom of N, calculate the mass percent of NO available from nitroglycerin

The carat is the unit of mass used by jewelers. One carat is exactly 200 mg. How many carbon atoms are present in a 24-carat diamond?

An iron bar weighed 664 g. After the bar had been standing in moist air for a month, exactly one- eighth of the iron turned to rust (Fe2O3). Calculate the final mass of the iron bar and rust

A certain metal oxide has the formula MO where M denotes the metal. A 39.46-g sample of the compound is strongly heated in an atmosphere of hydrogen to remove oxygen as water molecules. At the end, 31.70 g of the metal is left over. If O has an atomic mass of 16.00 amu, calculate the atomic mass of M and identify the element.

An impure sample of zinc (Zn) is treated with an excess of sulfuric acid (H2SO4) to form zinc sulfate (ZnSO4) and molecular hydrogen (H2). (a) Write a balanced equation for the reaction. (b) If 0.0764 g of H2 is obtained from 3.86 g of the sample, calculate the percent purity of the sample. (c) What assumptions must you make in (b)?

One of the reactions that occurs in a blast furnace, where iron ore is converted to cast iron, is Fe2O3 1 3CO 2Fe 1 3CO2 Suppose that 1.64 3 103 kg of Fe are obtained from a 2.62 3 103 -kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the percent purity of Fe2O3 in the original sample?

Carbon dioxide (CO2) is the gas that is mainly responsible for global warming (the greenhouse effect). The burning of fossil fuels is a major cause of the increased concentration of CO2 in the atmosphere. Carbon dioxide is also the end product of metabolism (see Example 3.13). Using glucose as an example of food, calculate the annual human production of CO2 in grams, assuming that each person consumes 5.0 3 102 g of glucose per day. The worlds population is 7.2 billion, and there are 365 days in a year.

Carbohydrates are compounds containing carbon, hydrogen, and oxygen in which the hydrogen to oxygen ratio is 2:1. A certain carbohydrate contains 40.0 percent carbon by mass. Calculate the empirical and molecular formulas of the compound if the approximate molar mass is 178 g.

Which of the following has the greater mass: 0.72 g of O2 or 0.0011 mole of chlorophyll (C55H72MgN4O5)?

Analysis of a metal chloride XCl3 shows that it contains 67.2 percent Cl by mass. Calculate the molar mass of X and identify the element.

Hemoglobin (C2952H4664N812O832S8Fe4) is the oxygen carrier in blood. (a) Calculate its molar mass. (b) An average adult has about 5.0 L of blood. Every milliliter of blood has approximately 5.0 3 109 erythrocytes, or red blood cells, and every red blood cell has about 2.8 3 108 hemoglobin molecules. Calculate the mass of hemoglobin molecules in grams in an average adult.

Myoglobin stores oxygen for metabolic processes in muscle. Chemical analysis shows that it contains 0.34 percent Fe by mass. What is the molar mass of myoglobin? (There is one Fe atom per molecule.)

Calculate the number of cations and anions in each of the following compounds: (a) 0.764 g of CsI, (b) 72.8 g of K2Cr2O7, (c) 6.54 g of Hg2(NO3)2.

A mixture of NaBr and Na2SO4 contains 29.96 percent Na by mass. Calculate the percent by mass of each compound in the mixture

Consider the reaction 3A 1 2B S 3C. A student mixed 4.0 moles of A with 4.0 moles of B and obtained 2.8 moles of C. What is the percent yield of the reaction?

Balance the following equation shown in molecular models. 1 1

Aspirin or acetyl salicylic acid is synthesized by reacting salicylic acid with acetic anhydride: C7H6O3 1 C4H6O3 C9H8O4 1 C2H4O2 salicylic acid acetic anhydride aspirin acetic acid (a) How much salicylic acid is required to produce 0.400 g of aspirin (about the content in a tablet), assuming acetic anhydride is present in excess? (b) Calculate the amount of salicylic acid needed if only 74.9 percent of salicylic acid is converted to aspirin. (c) In one experiment, 9.26 g of salicylic acid is reacted with 8.54 g of acetic anhydride. Calculate the theoretical yield of aspirin and the percent yield if only 10.9 g of aspirin is produced

Calculate the percent composition by mass of all the elements in calcium phosphate [Ca3(PO4)2], a major component of bone.

Lysine, an essential amino acid in the human body, contains C, H, O, and N. In one experiment, the complete combustion of 2.175 g of lysine gave 3.94 g CO2 and 1.89 g H2O. In a separate experiment, 1.873 g of lysine gave 0.436 g NH3. (a) Calculate the empirical formula of lysine. (b) The approximate molar mass of lysine is 150 g. What is the molecular formula of the compound?

Does 1 g of hydrogen molecules contain as many H atoms as 1 g of hydrogen atoms?

Avogadros number has sometimes been described as a conversion factor between amu and grams. Use the fluorine atom (19.00 amu) as an example to show the relation between the atomic mass unit and the gram

The natural abundances of the two stable isotopes of hydrogen (hydrogen and deuterium) are 1 1H: 99.985 percent and 2 1H: 0.015 percent. Assume that water exists as either H2O or D2O. Calculate the number of D2O molecules in exactly 400 mL of water. (Density 5 1.00 g/mL.)

A compound containing only C, H, and Cl was examined in a mass spectrometer. The highest mass peak seen corresponds to an ion mass of 52 amu. The most abundant mass peak seen corresponds to an ion mass of 50 amu and is about three times as intense as the peak at 52 amu. Deduce a reasonable molecular formula for the compound and explain the positions and intensities of the mass peaks mentioned. (Hint: Chlorine is the only element that has isotopes in comparable abundances: 35 17Cl: 75.5 percent; 35 17Cl: 24.5 percent. For H, use 1 1H; for C, use 12 1C.)

In the formation of carbon monoxide, CO, it is found that 2.445 g of carbon combine with 3.257 g of oxygen. What is the atomic mass of oxygen if the atomic mass of carbon is 12.01 amu?

What mole ratio of molecular chlorine (Cl2) to molecular oxygen (O2) would result from the breakup of the compound Cl2O7 into its constituent elements?

Which of the following substances contains the greatest mass of chlorine? (a) 5.0 g Cl2, (b) 60.0 g NaClO3, (c) 0.10 mol KCl, (d) 30.0 g MgCl2, (e) 0.50 mol Cl2.

A compound made up of C, H, and Cl contains 55.0 percent Cl by mass. If 9.00 g of the compound contain 4.19 3 1023 H atoms, what is the empirical formula of the compound?

Platinum forms two different compounds with chlorine. One contains 26.7 percent Cl by mass, and the other contains 42.1 percent Cl by mass. Determine the empirical formulas of the two compounds.

The following reaction is stoichiometric as written C4H9Cl 1 NaOC2H5 C4H8 1 C2H5OH 1 NaCl but it is often carried out with an excess of NaOC2H5 to react with any water present in the reaction mixture that might reduce the yield. If the reaction shown was carried out with 6.83 g of C4H9Cl, how many grams of NaOC2H5 would be needed to have a 50 percent molar excess of that reactant?

Compounds containing ruthenium(II) and bipyridine, C10H8N2, have received considerable interest because of their role in systems that convert solar energy to electricity. The compound [Ru(C10H8N2)3] Cl2 is synthesized by reacting RuCl3 ? 3H2O(s) with three molar equivalents of C10H8N2(s), along with an excess of triethylamine, N(C2H5)3(l), to convert ruthenium(III) to ruthenium(II). The density of triethylamine is 0.73 g/mL, and typically eight molar equivalents are used in the synthesis. (a) Assuming that you start with 6.5 g of RuCl3 ? 3H2O, how many grams of C10H8N2 and what volume of N(C2H5)3 should be used in the reaction? (b) Given that the yield of this reaction is 91 percent, how many grams of [Ru(C10H8N2)3]Cl2 will be obtained?

Heating 2.40 g of the oxide of metal X (molar mass of X 5 55.9 g/mol) in carbon monoxide (CO) yields the pure metal and carbon dioxide. The mass of the metal product is 1.68 g. From the data given, show that the simplest formula of the oxide is X2O3 and write a balanced equation for the reaction

A compound X contains 63.3 percent manganese (Mn) and 36.7 percent O by mass. When X is heated, oxygen gas is evolved and a new compound Y containing 72.0 percent Mn and 28.0 percent O is formed. (a) Determine the empirical formulas of X and Y. (b) Write a balanced equation for the conversion of X to Y

The formula of a hydrate of barium chloride is BaCl2 ? xH2O. If 1.936 g of the compound gives 1.864 g of anhydrous BaSO4 upon treatment with sulfuric acid, calculate the value of x

It is estimated that the day Mt. St. Helens erupted (May 18, 1980), about 4.0 3 105 tons of SO2 were released into the atmosphere. If all the SO2 were eventually converted to sulfuric acid, how many tons of H2SO4 were produced?

Cysteine, shown here, is one of the 20 amino acids found in proteins in humans. Write the molecular formula and calculate its percent composition by mass. S H C O

Isoflurane, shown here, is a common inhalation anesthetic. Write its molecular formula and calculate its percent composition by mass. F C O Cl H

A mixture of CuSO4 ? 5H2O and MgSO4 ? 7H2O is heated until all the water is lost. If 5.020 g of the mixture gives 2.988 g of the anhydrous salts, what is the percent by mass of CuSO4 ? 5H2O in the mixture?

When 0.273 g of Mg is heated strongly in a nitrogen (N2) atmosphere, a chemical reaction occurs. The product of the reaction weighs 0.378 g. Calculate the empirical formula of the compound containing Mg and N. Name the compound.

A mixture of methane (CH4) and ethane (C2H6) of mass 13.43 g is completely burned in oxygen. If the total mass of CO2 and H2O produced is 64.84 g, calculate the fraction of CH4 in the mixture.

Leaded gasoline contains an additive to prevent engine knocking. On analysis, the additive compound is found to contain carbon, hydrogen, and lead (Pb) (hence, leaded gasoline). When 51.36 g of this compound are burned in an apparatus such as that shown in Figure 3.6, 55.90 g of CO2 and 28.61 g of H2O are produced. Determine the empirical formula of the gasoline additive.

Because of its detrimental effect on the environment, the lead compound described in Problem 3.148 has been replaced by methyl tert-butyl ether (a compound of C, H, and O) to enhance the performance of gasoline. (This compound is also being phased out because of its contamination of drinking water.) When 12.1 g of the compound are burned in an apparatus like the one shown in Figure 3.6, 30.2 g of CO2 and 14.8 g of H2O are formed. What is the empirical formula of the compound?

Suppose you are given a cube made of magnesium (Mg) metal of edge length 1.0 cm. (a) Calculate the number of Mg atoms in the cube. (b) Atoms are spherical in shape. Therefore, the Mg atoms in the cube cannot fill all of the available space. If only 74 percent of the space inside the cube is taken up by Mg atoms, calculate the radius in picometers of a Mg atom. (The density of Mg is 1.74 g/cm3 and the volume of a sphere of radius r is 4 3r 3 .)

A certain sample of coal contains 1.6 percent sulfur by mass. When the coal is burned, the sulfur is converted to sulfur dioxide. To prevent air pollution, this sulfur dioxide is treated with calcium oxide (CaO) to form calcium sulfite (CaSO3). Calculate the daily mass (in kilograms) of CaO needed by a power plant that uses 6.60 3 106 kg of coal per day

Air is a mixture of many gases. However, in calculating its molar mass we need consider only the three major components: nitrogen, oxygen, and argon. Given that one mole of air at sea level is made up of 78.08 percent nitrogen, 20.95 percent oxygen, and 0.97 percent argon, what is the molar mass of air?

(a) Determine the mass of calcium metal that contains the same number of moles as 89.6 g of zinc metal. (b) Calculate the number of moles of molecular fluorine that has the same mass as 36.9 moles of argon. (c) What is the mass of sulfuric acid that contains 0.56 mole of oxygen atoms? (d) Determine the number of moles of phosphoric acid that contains 2.12 g of hydrogen atoms

A major industrial use of hydrochloric acid is in metal pickling. This process involves the removal of metal oxide layers from metal surfaces to prepare them for coating. (a) Write an equation between iron(III) oxide, which represents the rust layer over iron, and HCl to form iron(III) chloride and water. (b) If 1.22 moles of Fe2O3 and 289.2 g of HCl react, how many grams of FeCl3 will be produced?

Octane (C8H18) is a component of gasoline. Complete combustion of octane yields H2O and CO2. Incomplete combustion produces H2O and CO, which not only reduces the efficiency of the engine using the fuel but is also toxic. In a certain test run, 1.000 gal of octane is burned in an engine. The total mass of CO, CO2, and H2O produced is 11.53 kg. Calculate the efficiency of the process; that is, calculate the fraction of octane converted to CO2. The density of octane is 2.650 kg/gal.

Industrially, hydrogen gas can be prepared by reacting propane gas (C3H8) with steam at about 4008C. The products are carbon monoxide (CO) and hydrogen gas (H2). (a) Write a balanced equation for the reaction. (b) How many kilograms of H2 can be obtained from 2.84 3 103 kg of propane?

In a natural product synthesis, a chemist prepares a complex biological molecule entirely from nonbiological starting materials. The target molecules are often known to have some promise as therapeutic agents, and the organic reactions that are developed Interpreting, Modeling & Estimating 3.166 While most isotopes of light elements such as oxygen and phosphorus contain relatively equal numbers of protons and neutrons, recent results indicate that a new class of isotopes called neutron-rich isotopes can be prepared. These neutron-rich isotopes push the limits of nuclear stability as the large number of neutrons approach the neutron drip line. They may play a critical role in the nuclear reactions of stars. An unusually heavy isotope of aluminum ( 43 13Al) has been reported. How many more neutrons does this atom contain compared to an average aluminum atom? 3.167 Without doing any detailed calculations, arrange the following substances in the increasing order of number of moles: 20.0 g Cl, 35.0 g Br, and 94.0 g I. 3.168 Without doing any detailed calculations, estimate which element has the highest percent composition by mass in each of the following compounds: (a) Hg(NO3)2 (b) NF3 (c) K2Cr2O7 (d) C2952H4664N812O832S8Fe4 along the way benefit all chemists. The overall synthesis, however, requires many steps, so it is important to have the best possible percent yields at each step. What is the overall percent yield for such a synthesis that has 24 steps with an 80 percent yield at each step?

What is wrong or ambiguous with each of the statements here? (a) NH4NO2 is the limiting reagent in the reaction NH4NO2(s) N2(g) 1 2H2O(l) (b) The limiting reagents for the reaction shown here are NH3 and NaCl. NH3(aq) 1 NaCl(aq) 1 H2CO3(aq) NaHCO3(aq) 1 NH4Cl(aq)

(a) For molecules having small molecular masses, mass spectrometry can be used to identify their formulas. To illustrate this point, identify the molecule that most likely accounts for the observation of a peak in a mass spectrum at: 16 amu, 17 amu, 18 amu, and 64 amu. (b) Note that there are (among others) two likely molecules that would give rise to a peak at 44 amu, namely, C3H8 and CO2. In such cases, a chemist might try to look for other peaks generated when some of the molecules break apart in the spectrometer. For example, if a chemist sees a peak at 44 amu and also one at 15 amu, which molecule is producing the 44-amu peak? Why? (c) Using the following precise atomic masses 1 H (1.00797 amu), 12C (12.00000 amu), and 16O (15.99491 amu)how precisely must the masses of C3H8 and CO2 be measured to distinguish between them?

Potash is any potassium mineral that is used for its potassium content. Most of the potash produced in the United States goes into fertilizer. The major sources of potash are potassium chloride (KCl) and potassium sulfate (K2SO4). Potash production is often reported as the potassium oxide (K2O) equivalent or the amount of K2O that could be made from a given mineral. (a) If KCl costs $0.55 per kg, for what price (dollar per kg) must K2SO4 be sold to supply the same amount of potassium on a per dollar basis? (b) What mass (in kg) of K2O contains the same number of moles of K atoms as 1.00 kg of KCl?

A 21.496-g sample of magnesium is burned in air to form magnesium oxide and magnesium nitride. When the products are treated with water, 2.813 g of gaseous ammonia are generated. Calculate the amounts of magnesium nitride and magnesium oxide formed.

A certain metal M forms a bromide containing 53.79 percent Br by mass. What is the chemical formula of the compound?

A sample of iron weighing 15.0 g was heated with potassium chlorate (KClO3) in an evacuated container. The oxygen generated from the decomposition of KClO3 converted some of the Fe to Fe2O3. If the combined mass of Fe and Fe2O3 was 17.9 g, calculate the mass of Fe2O3 formed and the mass of KClO3 decomposed.

A sample containing NaCl, Na2SO4, and NaNO3 gives the following elemental analysis: Na: 32.08 percent; O: 36.01 percent; Cl: 19.51 percent. Calculate the mass percent of each compound in the sample

A sample of 10.00 g of sodium reacts with oxygen to form 13.83 g of sodium oxide (Na2O) and sodium peroxide (Na2O2). Calculate the percent composition of the mixture

While most isotopes of light elements such as oxygen and phosphorus contain relatively equal numbers of protons and neutrons, recent results indicate that a new class of isotopes called neutron- rich isotopes can be prepared. These neutron-rich isotopes push the limits of nuclear stability as the large number of neutrons approach the neutron drip line. They may play a critical role in the nuclear reactions of stars. An unusually heavy isotope of aluminum ( 43 13Al) has been reported. How many more neutrons does this atom contain compared to an average aluminum atom?

Without doing any detailed calculations, arrange the following substances in the increasing order of number of moles: 20.0 g Cl, 35.0 g Br, and 94.0 g I.

Without doing any detailed calculations, estimate which element has the highest percent composition by mass in each of the following compounds: (a) Hg(NO3)2 (b) NF3 (c) K2Cr2O7 (d) C2952H4664N812O832S8Fe4

Consider the reaction 6Li(s) 1 N2(g) 2Li3N(s) Without doing any detailed calculations, choose one of the following combinations in which nitrogen is the limiting reagent: (a) 44 g Li and 38 g N2 (b) 1380 g Li and 842 g N2 (c) 1.1 g Li and 0.81 g N2

Estimate how high in miles you can stack up an Avogadros number of oranges covering the entire Earth

The following is a crude but effective method for estimating the order of magnitude of Avogadros

How do the properties of compounds compare to the properties of the elements from which they are composed?

What is the empirical formula of a compound with the molecular formula C10H8? a) C5H3 b) C2H4 c) C5H4 d) CH

What is a chemical bond? Explain the difference between an ionic bond and a covalent bond.

Which substance is an ionic compound? a) SrI2 b) N2O4 c) He d) CCl4c

Explain the different ways to represent compounds. Why are there so many?

What is the correct formula for the compound formed between calcium and sulfur? a) CaS b) Ca2S c) CaS2 d) CaS3

What is the difference between an empirical formula and a molecular formula?

Name the compound SrI2 . a) strontium iodide b) strontium diiodide c) strontium(II) iodide d) strontium(II) diiodide

Define and provide an example for each of the following: atomic element, molecular element, ionic compound, molecular compound.

What is the formula for manganese(IV) oxide? a) Mn4O b) MnO4 c) Mn2O d) MnO2

Explain how to write a formula for an ionic compound given the names of the metal and nonmetal (or polyatomic ion) in the compound.

Name the compound Pb(C2H3O2)2. a) lead(II) carbonate b) lead(II) acetate c) lead bicarbonate d) lead diacetate

Explain how to name binary ionic compounds. How do you name an ionic compound if it contains a polyatomic ion?

Name the compound P2I4. a) phosphorus iodide b) phosphorus diiodide c) phosphorus(II) iodide d) diphosphorus tetraiodide

Why do the names of some ionic compounds include the charge of the metal ion while others do not?

Name the compound HNO2(aq). a) hydrogen nitrogen dioxide b) hydrogen nitrate c) nitric acid d) nitrous acid

Explain how to name molecular inorganic compounds.

How many atoms are specified by these prefixes: mono -, di -, tri -, tetra -, penta -, hexa -?

Determine the number of CH2Cl2 molecules in 25.0 g CH2Cl2. a) 0.294 molecules b) 1.77 x 1023 molecules c) 1.28 x 1027 molecules d) 1.51 x 1025 molecules

List the elements in the compound CF2Cl2 in order of decreasing mass percent composition. a) C > F > Cl b) F > Cl > C c) Cl > C > F d) Cl > F > C

Explain how to name binary and oxy acids.

Problem 11SAQ Determine the mass of potassium in 35.5 g of KBr. a) 17.4 g b) 0.298 g c) 11.7 g d) 32.9 g

What is the formula mass for a compound? Why is it useful?

A compound is 52.14% C, 13.13% H, and 34.73% O by mass. What is the empirical formula of the compound? a) C2H8O3 b) C2H6O c) C4HO3 d) C3HO6

Explain how the information in a chemical formula can be used to determine how much of a particular element is present in a given amount of a compound. Provide some examples of why this might be important.

A compound has the empirical formula CH2O and a formula mass of 120.10 amu. What is the molecular formula of the compound? a) CH2O b) C2H4O2 c) C3H6O3 d) C4H8O4

What is mass percent composition? Why is it useful?

Combustion of 30.42 g of a compound containing only carbon, hydrogen, and oxygen produces 35.21 g CO2 and 14.42 g H2O. What is the empirical formula of the compound? a) C4H8O6 b) C2H4O3 c) C2H2O3 d) C6HO12

What kinds of conversion factors are inherent in chemical formulas? Provide an example.

What are the correct coeff cients (reading from left to right) when the chemical equation is balanced? a) 1, 3, 1, 3 b) 1, 2, 1, 1 c) 1, 3, 2, 1 d) 3, 6, 1, 9

What kind of chemical formula can be obtained from experimental data showing the relative masses of the elements in a compound?

How can a molecular formula be obtained from an empirical formula? What additional information is required?

Which elements are normally present in organic compounds?

What is combustion analysis? What is it used for?

What is the difference between an alkane, an alkene, and an alkyne?

What are functionalized hydrocarbons? Give an example of a functionalized hydrocarbon.

Write a generic formula for each of the families of organic compounds. a. alcohols b. ethers c. aldehydes d. ketones e. carboxylic acids f. esters g. amines

Determine the number of each type of atom in each formula: a. Ca(NO2)2 b. CuSO4 c. Al(NO3)3 d. Mg(HCO3)2

Determine the number of each type of atom in each formula: a. \(\mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) b. \(\mathrm{BaCl}_{2}\) c. \(\mathrm{Fe}\left(\mathrm{NO}_{2}\right)_{2}\) d. \(\mathrm{Ca}(\mathrm{OH})_{2}\)

Write a chemical formula for each molecular model. (See Appendix IIA for color codes.)

Write a chemical formula for each molecular model. (See Appendix IIA for color codes.)

Classify each element as atomic or molecular. a. neon b. fluorine c. potassium d. nitrogen

Identify the elements that have molecules as their basic units a. hydrogen b. iodine c. lead d. oxygen

Classify each compound as ionic or molecular. a. \(\mathrm{CF}_{2} \mathrm{Cl}_{2}\) b. \(\mathrm{CCl}_{4}\) c. \(\mathrm{PtO}_{2}\) d. \(\mathrm{SO}_{3}\)

Classify each compound as ionic or molecular. a. CO2 b. NiCl2 c. NaI d. PCl3

Based on the molecular views, classify each substance as an atomic element, a molecular element, an ionic compound, or a molecular compound.

Based on the molecular views, classify each substance as an atomic element, a molecular element, an ionic compound, or a molecular compound.

Write a formula for the ionic compound that forms between each pair of elements. a. calcium and oxygen b. zinc and sulfur c. rubidium and bromine d. aluminum and oxygen

Write a formula for the ionic compound that forms between each pair of elements. a. silver and chlorine b. sodium and sulfur c. aluminum and sulfur d. potassium and chlorine

Write a formula for the compound that forms between calcium and each polyatomic ion. a. hydroxide b. chromate c. phosphate d. cyanide

Write a formula for the compound that forms between potassium and each polyatomic ion. a. carbonate b. phosphate c. hydrogen phosphate d. acetate

Name each ionic compound. a. \(\mathrm{Mg}_3\mathrm{N}_2\) b. KF c. \(\mathrm{Na}_{2} \mathrm{O}\) d. \(\mathrm{Li}_2\mathrm{S}\) e. CsF f. Kl

Give each ionic compound an appropriate name. a. \(\mathrm{SnO}\) b. \(\mathrm{Cr}_2 \mathrm{~S}_3\) c. \(\mathrm{RbI}\) d. \(\mathrm{BaBr}_2\)

Name each ionic compound. a. SnCl4 b. PbI2 c. Fe2O3 d. CuI2 e. HgBr2 f. CrCl2

Give each ionic compound an appropriate name. a. BaS b. FeCl3 c. PbI4 d. SrBr2

Name each ionic compound containing a polyatomic ion. a. CuNO2 b. Mg(C2H3O2)2 c. Ba(NO3)2 d. Pb(C2H3O2)2

Name each ionic compound containing a polyatomic ion. a. Ba(OH)2 b. NH4I c. NaBrO2 d. Fe(OH)3

Write a formula for each ionic compound. a. sodium hydrogen sulfite b. lithium permanganate c. silver nitrate d. potassium sulfate e. rubidium hydrogen sulfate f. potassium hydrogen carbonate

Write a formula for each ionic compound. a. copper(II) chloride b. copper(I) iodate c. lead(II) chromate d. calcium fluoride e. potassium hydroxide f. iron(II) phosphate

Write the name from the formula or the formula from the name for each hydrated ionic compound. a. CoSO4 7H2O b. iridium(III) bromide tetrahydrate c. Mg(BrO3)2 6H2O d. potassium carbonate dihydrate

Write the name from the formula or the formula from the name for each hydrated ionic compound. a. cobalt(II) phosphate octahydrate b. BeCl2 2H2O c. chromium(III) phosphate trihydrate d. LiNO2 H2O

Name each molecular compound. a. CO b. NI3 c. SiCl4 d. N4Se4

Name each molecular compound. a. \(\mathrm{SO}_{3}\) b. \(\mathrm{SO}_{2}\) c. \(\mathrm{BrF}_{5}\) d. NO

Problem 49E Write a formula for each molecular compound. a. phosphorus trichloride b. chlorine monoxide c. disulfur tetrafluoride d. phosphorus pentafluoride

Problem 50E Write a formula for each molecular compound. a. boron tribromide b. dichlorine monoxide c. xenon tetrafluoride d. carbon tetrabromide

Name each acid. a. HI(aq) b. HNO3(aq) c. H2CO3(aq)

Name each acid. a. HCl(aq) b. HClO2(aq) c. H2SO4(aq)

Problem 53E Mite formulas for each acid. a. hydrofluoric acid b. hydrobromic acid c. sulfurous acid

Problem 54E Mite formulas for each acid. a. phosphoric acid b. hydrocyanic acid c. chlorous acid

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. SrCl2 b. SnO2 c. P2S5 d. HC2H3O2(aq)

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. KClO3 b. I2O5 c. PbSO4

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. HNO2(aq) b. B2Cl2 c. BaCl2 d. CrCl3

Calculate the formula mass for each compound. a. NO2 b. C4H10 c. C6H12O6 d. Cr(NO3)3

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. XeO3 b. KClO c. CoSO4

Calculate the formula mass for each compound. a. MgBr2 b. HNO2 c. CBr4 d. Ca(NO3)2

Calculate the number of moles in each sample. a. 72.5 g CCl4 b. 12.4 g C12H22O11 c. 25.2 kg C2H2 d. 12.3 g of dinitrogen monoxide

Determine the number of moles (of molecules or formula units) in each sample. a. 25.5 g NO2 b. 1.25 kg CO2 c. 38.2 g KNO3 d. 155.2 kg Na2SO4

Calculate the mass of each sample. a. \(15.7\mathrm{\ mol\ }\mathrm{HNO}_3\) b. \(1.04\times10^{-3}\mathrm{\ mol}\mathrm{\ H}_2\mathrm{O}_2\) c. \(72.1\mathrm{\ mmol}\mathrm{\ SO}_2\) d. 1.23 mol xenon difluoride

Determine the number of moles (of molecules or formula units) in each sample. a. 55.98 g CF2Cl2 b. 23.6 kg Fe(NO3)2 c. 0.1187 g C8H18 d. 195 kg CaO

How many molecules are in each sample? a. 6.5 g H2O b. 389 g CBr4 c. 22.1 g O2 d. 19.3 g C8H10

How many molecules (or formula units) are in each sample? a 85.26 g CCl4 b. 55.93 kg NaHCO3 c. 119.78 g C4H10 d. 4.59 x 105 g Na3PO4

Calculate the mass (in g) of each sample. a. 5.94 x 1020 SO3 molecules b. 2.8 x 1022 H2O molecules c. 1 glucose molecule (C6H12O6)

Calculate the mass (in g) of each sample. a. 4.5 x 1025 O3 molecules b. 9.85 x 1019 CCl2F2 molecules c. 1 water molecule

Problem 70E A salt crystal has a mass of 0.12 mg. How many NaCI formula units does it contain?

Calculate the mass percent composition of nitrogen in each nitrogen-containing compound. a. N2O b. NO c. NO2 d. HNO3

Copper(II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine (in g) contained in 55.5 g of copper(II) fluoride.

Most fertilizers consist of nitrogen-containing compounds such as NH3, CO(NH2)2, NH4NO3, and (NH4)2SO4. The nitrogen content in these compounds is used for protein synthesis by plants. Calculate the mass percent composition of nitrogen in each of the fertilizers named. Which fertilizer has the highest nitrogen content?

Silver chloride, often used in silver plating, contains 75.27% Ag by mass. Calculate the mass of silver chloride required to plate 155 mg of pure silver.

The iodide ion is a dietary mineral essential to good nutrition. In countries where potassium iodide is added to salt, iodine deficiency (or goiter) has been almost completely eliminated. The recommended daily allowance (RDA) for iodine is 150 g/day . How much potassium iodide (76.45% I) should you consume if you want to meet the RDA?

Problem 78E The American Dental Association recommends that an adult female should consume 3.0 mg of fluoride (F-) per day to prevent tooth decay. If the fluoride is consumed in the form of sodium fluoride (45.24% F), what amount of sodium fluoride contains the recommended amount of fluoride?

Write a ratio showing the relationship between the molar amounts of each element for each compound. (See Appendix IIA for color codes.)

Determine the number of moles of hydrogen atoms in each sample. a. 0.0885 mol C4H10 b. 1.3 mol CH4 c. 2.4 mol C6H12 d. 1.87 mol C8H18

Determine the number of moles of oxygen atoms in each s ample. a. 4.88 mol H2O2 b. 2.15 mol N2O c. 0.0237 mol H2CO3 d. 24.1 mol CO2

Calculate mass (in grams) of sodium in 8.5 g of each sodium containing food additive. a. NaCl (table salt) b. Na3PO4 (sodium phosphate) c. NaC7H5O2 (sodium benzoate) d. Na2C6H6O7 (sodium hydrogen citrate)

Calculate the mass (in kilograms) of chlorine in 25 kg of each chlorofluorocarbon (CFC). a. CF2Cl2 b. CFCl3 c. C2F3Cl3 d. CF3Cl

A chemist decomposes samples of several compounds; the masses of their constituent elements are shown below. Calculate the empirical formula for each compound. a. 1.651 g Ag, 0.1224 g O b. 0.672 g Co, 0.569 g As, 0.486 g O c. 1.443 g Se, 5.841 g Br

Problem 86E A chemist decomposes samples of several compounds; the masses of their constituent elements are shown below. Calculate the empirical formula for each compound. a. 1.245 g Ni. 5.381 g I b. 2.677 g Ba, 3.115 g Br c. 2.128 g Be, 7.557 g S, 15.107 g O

Problem 87E Calculate the empirical formula for each stimulant based on its elemental mass percent composition. a. nicotine (found in tobacco leaves): C 74.03%, H 8.70%, N 17.27% b. caffeine (found in coffee beans): C 49.48%, H 5.19%, N 28.85%, O 16.48%

Problem 88E Calculate the empirical formula for each natural flavor based on its elemental mass percent composition. a. methyl butyrate (component of apple taste and smell): C 53.80%, H 9.37%, O 31.33% b. vanillin (responsible for the taste and smell of vanilla): C 63.15%, H 5.30%, O 31.55%

Problem 89E The elemental mass percent composition of ibuprofen (an aspirin substitute) is 75.69% C, 8.80% H, and 15.51 % O. Determine the empirical formula of ibuprofen.

Problem 90E The elemental mass percent composition of ascorbic acid ( vitamin C) is 40.92% C, 4.58% H, and 54.50% O. Determine the empirical formula of ascorbic acid.

Problem 91E A 0.77 mg sample of nitrogen reacts with chlorine to form 6.61 mg of the chloride. Determine the empirical formula of nitrogen chloride.

Problem 92E A 45.2 mg sample of phosphorus reacts with selenium to form 131.6 mg of the selenide. Determine the empirical formula of phosphorus selenide.

The empirical formula and molar mass of several compounds are listed next. Find the molecular formula of each compound. a. C6H7N, 186.24 g/mol b. C2HCl, 181.44 g/mol c. C5H10NS2, 296.54 g/mol

The molar mass and empirical formula of several compounds are listed next. Find the molecular formula of each compound. a. C2H9, 114.22 g/mol b. CCl, 284.77 g/mol c. C3H2N, 312.29 g/mol

Combustion analysis of a hydrocarbon produced 33.01 g CO2 and 13.51 g H2O. Calculate the empirical formula of the hydrocarbon.

Combustion analysis of naphthalene, a hydrocarbon used in mothballs, produced 8.80 g \(\mathrm{CO}_{2}\) and 1.44 g \(\mathrm{H}_{2} \mathrm{O}\). Calculate the empirical formula for naphthalene.

The foul odor of rancid butter is due largely to butyric acid, a compound containing carbon, hydrogen, and oxygen. Combustion analysis of a 4.30 g sample of butyric acid produced 8.59 g CO2 and 3.52 g H2O. Determine the empirical formula for butyric acid.

Tartaric acid is the white, powdery substance that coats tart candies such as Sour Patch Kids. Combustion analysis of a 12.01 g sample of tartaric acid—which contains only carbon, hydrogen, and oxygen—produced 14.08 g CO2 and 4.32 g H2O. Determine the empirical formula for tartaric acid.

Problem 99E Sulfuric acid is a component of acid rain formed when gaseous sulfur dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous sulfuric acid. Write a balanced chemical equation for this reaction. (Note: this is a simplified representation of this reaction.)

Problem 100E Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid. Write a balanced chemical equation for this reaction. (Note: this is a simplified representation of this reaction.)

Problem 102E Wien iron rusts, solid iron reacts with gaseous oxygen to form solid iron(lll) oxide. Write a balanced chemical equation for this reaction.

Problem 101E In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. Write a balanced chemical equation for this reaction.

Write a balanced chemical equation for the fermentation of sucrose (C12H22O11) by yeasts in which the aqueous sugar reacts with water to form aqueous ethyl alcohol (C2H5OH) and carbon dioxide gas.

Write a balanced equation for the photosynthesis reaction in which gaseous carbon dioxide and liquid water react in the presence of chlorophyll to produce aqueous glucose (C6H12O6)and oxygen gas.

Write a balanced chemical equation for each reaction. a. Solid lead(II) sulfide reacts with aqueous hydrobromic acid to form solid lead(II) bromide and dihydrogen monosulfide gas. b. Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4) and liquid water. c. Aqueous hydrochloric acid reacts with solid manganese(IV) oxide to form aqueous manganese(II) chloride, liquid water, and chlorine gas. d. Liquid pentane (C5H12) reacts with gaseous oxygen to form carbon dioxide and liquid water.

Write a balanced chemical equation for each reaction. a. Solid copper reacts with solid sulfur to form solid copper(I) sulfide. b. Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water. c. Sulfur dioxide gas reacts with oxygen gas to form s ulfur trioxide gas. d. Gaseous ammonia (NH3) reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water

Problem 107E Write a balanced chemical equation for the reaction of aqueous sodium carbonate with aqueous copper(ll) chloride to form solid copper(ll) carbonate and aqueous sodium chloride.

Problem 108E Mite a balanced chemical equation for the reaction of aqueous potassium hydroxide with aqueous iron(lll) chloride to form solid iron(lll) hydroxide and aqueous potassium chloride

Balance each chemical equation. a. Na2S(aq) + Cu(NO3)2(aq) ? NaNO3(aq) + CuS(s) b. N2H4(l) ? NH3(g) + N2(g) c. HCl(aq) + O2(g) ? H2O(l) + Cl2(g) d. FeS(s) + HCl(aq) ? FeCl2(aq) + H2S(g)

Balance each chemical equation. a. \(\mathrm{CO}_2(g)+\mathrm{CaSiO}_3(s)+\mathrm{H}_2\mathrm{O}(l)\ \longrightarrow\mathrm{\ SiO}_2(s)+\mathrm{Ca}\left(\mathrm{HCO}_3\right)_2(aq)\) b. \(\mathrm{Co}\left(\mathrm{NO}_3\right)_3(aq)+\left(\mathrm{NH}_4\right)_2\mathrm{S}(aq)\ \longrightarrow\mathrm{\ Co}_2\mathrm{S}_3(s)+\mathrm{NH}_4\mathrm{NO}_3(aq)\) c. \(\mathrm{Cu}_2\mathrm{O}(s)+\mathrm{C}(s)\ \longrightarrow\ \mathrm{Cu}(s)+\mathrm{CO}(g)\) d. \(\mathrm{H}_{2}(g)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{HCl}(g)\)

Classify each compound as organic or inorganic. a. \(\mathrm{CaCO}_3\) b. \(\mathrm{C}_4 \mathrm{H}_8\) c. \(\mathrm{C}_4 \mathrm{H}_6 \mathrm{O}_6\) d. \(\mathrm{LiF}\)

Classify each compound as organic or inorganic. a. C8H18 b. CH3NH2 c. CaO d. FeCO3

Classify each hydrocarbon as an alkane, alkene, or alkyne.

Classify each hydrocarbon as an alkane, alkene, or alkyne.

Write a formula based on the name, or a name based on the formula, for each hydrocarbon. a. propane b. CH3CH2CH3 c. octane d. CH3CH2CH2CH2CH3

Write a formula based on the name, or a name based on the formula, for each hydrocarbon: a. CH3CH3 b. pentane c. CH3CH2CH2CH2CH2CH3 d. heptane

Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the family to which the compound belongs.

Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the family to which the compound belongs.

How many molecules of ethanol (\(C_2 H_5 OH\)) (the alcohol in alcoholic beverages) are present in 145 mL of ethanol? The density of ethanol is \(0.789 \ g/cm^3\).

A drop of water has a volume of approximately 0.05 mL. How many water molecules does it contain? The density of water is 1.0 g/cm3.

Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. potassium chromate b. lead(ll) phosphate c. sulfurous acid d. cobalt(ll) bromide

Problem 122E Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. perchloric acid b. phosphorus pentachloride c. nitrogen triiodide d. carbon dioxide

A Freon leak in the air-conditioning system of an old car releases 25 g of CF2Cl2 per month. What mass of chlorine does this car emit into the atmosphere each year?

A Freon leak in the air-conditioning system of a large building releases 12 kg of CHF2Cl per month. If the leak is allowed to continue, how many kilograms of Cl are emitted into the atmosphere each year?

A metal (M) forms a compound with the formula MCl3. If the compound contains 65.57% Cl by mass, what is the identity of the metal?

A metal (M) forms an oxide with the formula \(\mathrm{M}_{2} \mathrm{O}\). If the oxide contains 16.99% O by mass, what is the identity of the metal?

Problem 128E Fructose is a common sugar found in fruit. Elemental analysis of fructose gives the following mass percent composition: C 40.00%, H 6.72%, O 53.28%. The molar mass of fructose is 180.16 g/mol. Find the molecular formula of fructose.

Combustion analysis of a 13.42 g sample of equilin (which contains only carbon, hydrogen, and oxygen) produces 39.61 g CO2 and 9.01 g H2O. The molar mass of equilin is 268.34 g/mol. Find its molecular formula.

Problem 127E Estradiol is a female sexual hormone that causes maturation and maintenance of the female reproductive system. Elemental analysis of estradiol gives the following mass percent composition: C 79.37%, H 8.83%, O 11.75%. The molar mass of estradiol is 272.37 g/mol. Find the molecular formula of estradiol.

Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone that occurs in the urine of pregnant women. Combustion analysis of a 1.893 g sample of estrone produces 5.545 g of CO2 and 1.388 g H2O. The molar mass of estrone is 270.36 g/mol. Find its molecular formula.

Epsom salts is a hydrated ionic compound with the following formula: MgSO4 xH2O . A 4.93 g sample of Epsom salts was heated to drive off the water of hydration. The mass of the sample after complete dehydration was 2.41 g. Find the number of waters of hydration ( x ) in Epsom salts.

A hydrate of copper(II) chloride has the following formula: CuCl2 xH2O . The water in a 3.41 g sample of the hydrate was driven off by heating. The remaining sample had a mass of 2.69 g. Find the number of waters of hydration ( x ) in the hydrate.

Problem 133E A compound of molar mass 177 g/mol contains only carbon, hydrogen, bromine, and oxygen. Analysis reveals that the compound contains eight times as much carbon as hydrogen by mass. Find the molecular formula.

Researchers obtained the following data from experiments to find the molecular formula of benzocaine, a local anesthetic, which contains only carbon, hydrogen, nitrogen, and oxygen. Complete combustion of a \(3.54 \mathrm{~g}\) sample of benzocaine with excess \(\mathrm{O}_2\) formed \(8.49 \mathrm{~g}\) of \(\mathrm{CO}_2\) and \(2.14 \mathrm{~g} \mathrm{H}_2 \mathrm{O}\). Another sample of mass \(2.35 \mathrm{~g}\) was found to contain \(0.199 \mathrm{~g}\) of N. The molar mass of benzocaine was found to be \(165 \mathrm{~g} / \mathrm{mol}\). Find the molar formula of benzocaine.

Find the total number of atoms in a sample of cocaine hydrochloride, C17H22ClNO4, of mass 23.5 mg.

Vanadium forms four different oxides in which the percent by mass of vanadium is respectively (a) 76%, (b) 68%, (c) 61%, and (d) 56%. Determine the formula and the name of each one of these oxides.

The chloride of an unknown metal is believed to have the formula MCl3. A 2.395 g sample of the compound is found to contain 3.606 * 10-2 mol Cl . Find the atomic mass of M.

Write the structural formulas of three different compounds that each have the molecular formula C5H12.

A chromium-containing compound has the formula FexCryO4 and is 28.59% oxygen by mass. Find x and y .

A phosphorus compound that contains 34.00% phosphorus by mass has the formula X3P2. Identify the element X.

A particular brand of beef jerky contains 0.0552% sodium nitrite by mass and is sold in an 8.00 oz bag. What mass of sodium does the sodium nitrite contribute to sodium content of the bag of beef jerky?

Problem 142E Phosphorus is obtained primarily from ores containing calcium phosphate. If a particular ore contains 57.8% calcium phosphate, what minimum mass of the ore must be processed to obtain 1.00 kg of phosphorus?

Problem 143E A mixture of NaCI and NaBr has a mass of 2.00 g and contains 0.75 g of Na. What is the mass of NaBr in the mixture?

A mixture of CaCO3 and (NH4)2CO3 is 61.9% CO3 by mass. Find the mass percent of CaCO3 in the mixture

Three pure compounds form when 1.00 g samples of element X combine with, respectively, 0.472 g, 0.630 g, and 0.789 g of element Z. The first compound has the formula \(X_2 Z_3\). Find the empirical formulas of the other two compounds.

A mixture of 50.0 g of S and 1.00 x 102 g of Cl2 reacts completely to form S2Cl2 and SCl2. Find the mass of S2Cl2 formed.

Because of increasing evidence of damage to the ozone layer, chlorofluorocarbon (CFC) production was banned in 1996. However, there are about 100 million auto air conditioners in operation that still use CFC-12 (CF2Cl2) . These air conditioners are recharged from stockpiled supplies of CFC-12. If each of the 100 million automobiles contains 1.1 kg of CFC-12 and leaks 25% of its CFC-12 into the atmosphere per year, how much chlorine, in kg, is added to the atmosphere each year due to auto air conditioners? (Assume two significant figures in your calculations.)

A particular coal contains 2.55% sulfur by mass. When the coal is burned, it produces SO2 emissions, which combine with rainwater to produce sulfuric acid. Use the formula of sulfuric acid to calculate the mass percent of S in sulfuric acid. Then determine how much sulfuric acid (in metric tons) is produced by the combustion of 1.0 metric ton of this coal. (A metric ton is 1000 kg.)

Lead is found in Earth’s crust as several different lead ores. Suppose a certain rock is 38.0% PbS (galena), 25.0% \(\mathrm{PbCO}_{3}\) (cerussite), and 17.4% \(\mathrm{PbSO}_{4}\) (anglesite). The remainder of the rock is composed of substances containing no lead. How much of this rock (in kg) must be processed to obtain 5.0 metric tons of lead? (A metric ton is 1000 kg.)

Problem 151E A compound of molar mass 229 contains only carbon, hydrogen, iodine, and sulfur. Analysis shows that a sample of the compound contains 6 times as much carbon as hydrogen, by mass. Calculate the molecular formula of the compound.

A 2.52 g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess O to yield 4.23 g of CO2 and 1.01 g of H2O. Another sample of the same compound, of mass 4.14 g, yielded 2.11 g of SO3. A third sample, of mass 5.66 g, yielded 2.27 g of HNO3. Calculate the empirical formula of the compound.

Problem 152E The elements X and Y form a compound that is 40% X and 60% Y by mass. The atomic mass of X is twice that of Y. What is the empirical formula of the compound?

A compound of X and Y is \(\frac {1}{3}\) X by mass. The atomic mass of element X is \(\frac {1}{3}\) the atomic mass of element Y. Find the empirical formula of the compound.

A mixture of carbon and sulfur has a mass of 9.0 g. Complete combustion with excess O2 gives 23.3 g of a mixture of CO2 and SO2. Find the mass of sulfur in the original mixture.

Without doing any calculations, determine which element in each of the compounds will have the highest mass percent composition. a. CO b. N2O c. C6H12O6 d. NH3

When molecules are represented by molecular models, what does each sphere represent? How big is the nucleus of an atom in comparison to the sphere used to represent an atom in a molecular model?

Explain the problem with the following statement and correct it. “The chemical formula for ammonia (\(NH_3\)) indicates that ammonia contains three grams of hydrogen to each gram of nitrogen.”

Without doing any calculations, arrange the elements in H2SO4 in order of decreasing mass percent composition.

Problem 158E Explain the problem with the following statement and correct it. ‘When a chemical equation is balanced, the number of molecules of each type on both sides of the equation will be equal."

Problem 160E Element A is an atomic element and element B is a diatomic molecular element. Using circles to represent atoms of A and squares to represent atoms of B, draw molecular level views of each element.

Identify at least two points in Dominis article where she might have given way to accusation or blame or where she might have dismissed the Slow Food movement as being short-sighted or elitist. Discuss how, instead, she finds common ground and promotes dialogue with her audience through civil discourse.

Find a review of a movie, a television show, a concert, an album or a song, or another form of popular culture. Identify the claim in the review. What criteria does the reviewer use to justify a thumbs-up or a thumbs-down?

Read the following argument of policy that appeared as an editorial in the New York Times in 2004. Annotate it to identify claims of fact, value, and policy; then describe how these interact throughout the argument.

Modeled on the Declaration of Independence, the Declaration of Sentiments by Elizabeth Cady Stanton was presented on July 19, 1848, at the Seneca Falls Convention. Analyze the use of induction and deduction to support the claim and develop the argument.

Does the text tell or suggest a narrative or story? If so, what is the point?

What emotions does the visual text evoke? How do color or light and shadow contribute to evoking emotions?

Are the figures realistic, caricatures, distorted? What is the effect?

Are any of the images visual allusions that would evoke emotions or memories in viewers?

What cultural values are viewers likely to bring to the images?

What claim does the visual make about the issue(s) it addresses?

Does the text tell or suggest a narrative or story? If so, what is the point?

What emotions does the visual text evoke? How do color or light and shadow contribute to evoking emotions?

Are the figures realistic, caricatures, distorted? What is the effect?

Are any of the images visual allusions that would evoke emotions or memories in viewers?

What cultural values are viewers likely to bring to the images?

What claim does the visual make about the issue(s) it addresses?

What kind of chemical formula can be obtained from experimental data showing the relative masses of the elements in a compound?

How can a molecular formula be obtained from an empirical formula? What additional information is required?

What is combustion analysis? What is it used for?

Which elements are normally present in organic compounds?

What is the difference between an alkane, an alkene, and an alkyne?

What are functionalized hydrocarbons? Give an example of a functionalized hydrocarbon.

Write a generic formula for each of the families of organic compounds. a. alcohols b. ethers c. aldehydes d. ketones e. carboxylic acids f. esters g. amines

Determine the number of each type of atom in each formula: a. Mg3(PO4)2 b. BaCl2 c. Fe(NO2)2 d. Ca(OH)2

Determine the number of each type of atom in each formula: a. Ca(NO2)2 b. CuSO4 c. Al(NO3)3 d. Mg(HCO3)2

Write a chemical formula for each molecular model. (See Appendix IIA for color codes.)

Write a chemical formula for each molecular model. (See Appendix IIA for color codes.)

Classify each element as atomic or molecular. a. neon b. fluorine c. potassium d. nitrogen

Identify the elements that have molecules as their basic units. a. hydrogen b. iodine c. lead d. oxygen

Classify each compound as ionic or molecular. a. CO2 b. NiCl2 c. NaI d. PCl3

Classify each compound as ionic or molecular. a. CF2Cl2 b. CCl4 c. PtO2 d. SO3

Based on the molecular views, classify each substance as an atomic element, a molecular element, an ionic compound, or a molecular compound.

Based on the molecular views, classify each substance as an atomic element, a molecular element, an ionic compound, or a molecular compound.

Write a formula for the ionic compound that forms between each pair of elements. a. calcium and oxygen b. zinc and sulfur c. rubidium and bromine d. aluminum and oxygen

Write a formula for the ionic compound that forms between each pair of elements. a. silver and chlorine b. sodium and sulfur c. aluminum and sulfur d. potassium and chlorine

Write a formula for the compound that forms between calcium and each polyatomic ion. a. hydroxide b. chromate c. phosphate d. cyanide

Write a formula for the compound that forms between potassium and each polyatomic ion. a. carbonate b. phosphate c. hydrogen phosphate d. acetate

Name each ionic compound. (a) \(\mathrm{Mg}_3 \mathrm{~N}_2\) (b) \(\mathrm{KF}\) (c) \(\mathrm{Na}_2 \mathrm{O}\) (d) \(\mathrm{Li}_2 \mathrm{~S}\) (e) CsF (f) \(\mathrm{KI}\)

Name each ionic compound. a. SnCl4 b. PbI2 c. Fe2O3 d. CuI2 e. HgBr2 f. CrCl2

Give each ionic compound an appropriate name. a. SnO b. Cr2S3 c. RbI d. BaBr2

Give each ionic compound an appropriate name. a. BaS b. \(FeCl_3\) c. \(PbI_4\) d. \(SrBr_2\)

Name each ionic compound containing a polyatomic ion. a. CuNO2 b. Mg(C2H3O2)2 c. Ba(NO3)2 d. Pb(C2H3O2)2

Name each ionic compound containing a polyatomic ion. a. Ba(OH)2 b. NH4I c. NaBrO4 d. Fe(OH)3

Write a formula for each ionic compound. a. sodium hydrogen sulfite b. lithium permanganate c. silver nitrate d. potassium sulfate e. rubidium hydrogen sulfate f. potassium hydrogen carbonate

Write a formula for each ionic compound. a. copper(II) chloride b. copper(I) iodate c. lead(II) chromate d. calcium fluoride e. potassium hydroxide f. iron(II) phosphate

Write the name from the formula or the formula from the name for each hydrated ionic compound. a. \(\mathrm{CoSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\) b. iridium(III) bromide tetrahydrate c. \(\mathrm{Mg}\left(\mathrm{BrO}_{3}\right)_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) d. potassium carbonate dihydrate

Write the name from the formula or the formula from the name for each hydrated ionic compound. a. cobalt(II) phosphate octahydrate b. BeCl2 # 2H2O c. chromium(III) phosphate trihydrate d. LiNO2 # H2O

Name each molecular compound. a. CO b. NI3 c. SiCl4 d. N4Se4

Name each molecular compound. a. \(\mathrm{SO}_{3}\) b. \(\mathrm{SO}_{2}\) c. \(\mathrm{BrF}_{5}\) d. NO

Write a formula for each molecular compound. a. phosphorus trichloride b. chlorine monoxide c. disulfur tetrafluoride d. phosphorus pentafluoride

Write a formula for each molecular compound. a. boron tribromide b. dichlorine monoxide c. xenon tetrafluoride d. carbon tetrabromide

Name each acid. a. HI( aq ) b. HNO3 ( aq ) c. H2CO3 ( aq )

Name each acid. a. HCl( aq ) b. HClO2 ( aq ) c. H2SO4 ( aq )

Write formulas for each acid. a. hydrofluoric acid b. hydrobromic acid c. sulfurous acid

Write formulas for each acid. a. phosphoric acid b. hydrocyanic acid c. chlorous acid

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. SrCl 2 b. SnO 2 c. P 2 S 5 d. HC 2 H 3 O 2( aq)

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. HNO 2 ( aq ) b. B 2 Cl 2 c. BaCl 2 d. CrCl 3

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. KClO 3 b. I 2 O 5 c. PbSO 4

Use the nomenclature flow chart ( Figure 3.10 ) to name each compound. a. XeO 3 b. KClO c. CoSO 4

Calculate the formula mass for each compound. a. NO2 b. C4H10 c. C6H12O6 d. Cr(NO3)3

Calculate the formula mass for each compound. a. MgBr2 b. HNO2 c. CBr4 d. Ca(NO3)2

Calculate the number of moles in each sample. a. \(72.5 g CCl_4\) b. \(12.4 g C_12 H_22 O_11\) c. \(25.2 kg C_2 H_2\) d. 12.3 g of dinitrogen monoxide

Calculate the mass of each sample. a. 15.7 mol HNO 3 b. 1.04 10 3 mol H 2 O 2 c. 72.1 mmol SO 2 d. 1.23 mol xenon difluoride

Determine the number of moles (of molecules or formula units) in each sample. a. 25.5 g NO2 b. 1.25 kg CO2 c. 38.2 g KNO3 d. 155.2 kg Na2SO4

Determine the number of moles (of molecules or formula units) in each sample. a. 55.98 g CF2Cl2 b. 23.6 kg Fe(NO3)2 c. 0.1187 g C8H18 d. 195 kg CaO

How many molecules (or formula units) are in each sample? a 85.26 g CCl4 b. 55.93 kg NaHCO3 c. 119.78 g C4H10 d. 4.59 * 105 g Na3PO4

Calculate the mass (in g) of each sample. a. 5.94 * 1020 SO3 molecules b. 2.8 * 1022 H2O molecules c. 1 glucose molecule (C6H12O6

sugar crystal contains approximately 1.8 * 1017 sucrose (C12H22O11) molecules. What is its mass in mg?

A salt crystal has a mass of 0.12 mg. How many NaCl formula units does it contain?

Calculate the mass percent composition of carbon in each carbon-containing compound. a. CH4 b. C2H6 c. C2H2 d. C2H5Cl

Calculate the mass percent composition of nitrogen in each nitrogen-containing compound. a. N2O b. NO c. NO2

Most fertilizers consist of nitrogen-containing compounds such as NH3 , CO(NH2)2 , NH4NO3 , and (NH4)2SO4 . The nitrogen content in these compounds is used for protein synthesis by plants. Calculate the mass percent composition of nitrogen in each of the fertilizers named. Which fertilizer has the highest nitrogen content?

Iron in the earth is in the form of iron ore. Common ores include Fe2O3 (hematite), Fe3O4 (magnetite), and FeCO3 (siderite). Calculate the mass percent composition of iron for each of these iron ores. Which ore has the highest iron content?

Silver chloride, often used in silver plating, contains 75.27% Ag by mass. Calculate the mass of silver chloride required to plate 155 mg of pure silver.

Write a ratio showing the relationship between the molar amounts of each element for each compound. (See Appendix IIA for color codes.)

Combustion analysis of a hydrocarbon produced 33.01 g CO2 and 13.51 g H2O . Calculate the empirical formula of the hydrocarbon.

Write a balanced equation for the photosynthesis reaction in which gaseous carbon dioxide and liquid water react in the presence of chlorophyll to produce aqueous glucose (C6H12O6) and oxygen gas.

Write a balanced chemical equation for the reaction of aqueous potassium hydroxide with aqueous iron(III) chloride to form solid iron(III) hydroxide and aqueous potassium chloride.

Classify each hydrocarbon as an alkane, alkene, or alkyne. a. HCCH b. H3CiCHCiCH3 c. H3C CH CH3 CH3 d. H3CiCCiCH3

Classify each hydrocarbon as an alkane, alkene, or alkyne. a. HCCH b. H3CiCHCiCH3 c. H3C CH CH3 CH3 d. H3CiCCiCH3

Write a formula based on the name, or a name based on the formula, for each hydrocarbon. a. propane b. CH3CH2CH3 c. octane d. CH3CH2CH2CH2CH3

Write a formula based on the name, or a name based on the formula, for each hydrocarbon: a. CH3CH3 b. pentane c. CH3CH2CH2CH2CH2CH3 d. heptane

Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the family to which the compound belongs. a. H3CiCH2OH b. H3CiCH3 c. H3C CH C 2 O CH3 d. H3CiNH2

Classify each organic compound as a hydrocarbon or a functionalized hydrocarbon. For functionalized hydrocarbons, identify the family to which the compound belongs. a. H3C C OH O CH2 b. H3C CH O c. H3C C CH3 CH3 CH3 d. H3CiCH2iOiCH3

How many molecules of ethanol (C2H5OH) (the alcohol in alcoholic beverages) are present in 145 mL of ethanol? The density of ethanol is 0.789 g>cm3 .

Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. potassium chromate b. lead(II) phosphate c. sulfurous acid d. cobalt(II) bromide

Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. potassium chromate b. lead(II) phosphate c. sulfurous acid d. cobalt(II) bromide Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituentelement. a. potassium chromate b. lead(II) phosphate c. sulfurous acid d. cobalt(II) bromide

Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. a. perchloric acid b. phosphorus pentachloride c. nitrogen triiodide d. carbon dioxide

A Freon leak in the air-conditioning system of an old car releases 25 g of CF2Cl2 per month. What mass of chlorine does this car emit into the atmosphere each year?

A Freon leak in the air-conditioning system of a large building releases 12 kg of CHF2Cl per month. If the leak is allowed to continue, how many kilograms of Cl are emitted into the atmosphere each year?

A metal (M) forms a compound with the formula MCl3 . If the compound contains 65.57% Cl by mass, what is the identity of the metal?

A metal (M) forms an oxide with the formula \(\mathrm{M}_{2} \mathrm{O}\). If the oxide contains 16.99% O by mass, what is the identity of the metal?

Estradiol is a female sexual hormone that causes maturation and maintenance of the female reproductive system. Elemental analysis of estradiol gives the following mass percent composition: C 79.37%, H 8.88%, O 11.75%. The molar mass of estradiol is 272.37 g>mol. Find the molecular formula of estradiol

Fructose is a common sugar found in fruit. Elemental analysis of fructose gives the following mass percent composition: C 40.00%, H 6.72%, O 53.28%. The molar mass of fructose is 180.16 g>mol. Find the molecular formula of fructose.

Combustion analysis of a 13.42 g sample of equilin (which contains only carbon, hydrogen, and oxygen) produces 39.61 g CO2 and 9.01 g H2O . The molar mass of equilin is 268.34 g>mol. Find its molecular formula.

Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone that occurs in the urine of pregnant women. Combustion analysis of a 1.893 g sample of estrone produces 5.545 g of CO2 and 1.388 g H2O . The molar mass of estrone is 270.36 g>mol. Find its molecular formula.

Epsom salts is a hydrated ionic compound with the following formula: MgSO4 # xH2O . A 4.93 g sample of Epsom salts was heated to drive off the water of hydration. The mass of the sample after complete dehydration was 2.41 g. Find the number of waters of hydration ( x ) in Epsom salts.

A hydrate of copper(II) chloride has the following formula: CuCl2 # xH2O . The water in a 3.41 g sample of the hydrate was driven off by heating. The remaining sample had a mass of 2.69 g. Find the number of waters of hydration ( x ) in the hydrate

A compound of molar mass 177 g>mol contains only carbon, hydrogen, bromine, and oxygen. Analysis reveals that the compound contains 8 times as much carbon as hydrogen by mass. Find the molecular formula.

Researchers obtained the following data from experiments to find the molecular formula of benzocaine, a local anesthetic, which contains only carbon, hydrogen, nitrogen, and oxygen. Complete combustion of a 3.54 g sample of benzocaine with excess O2 formed 8.49 g of CO2 and 2.14 g H2O . Another sample of mass 2.35 g was found to contain 0.199 g of N. The molar mass of benzocaine was found to be 165 g>mol. Find the molar formula of benzocaine.

Find the total number of atoms in a sample of cocaine hydrochloride, \(\mathrm{C}_{17} \mathrm{H}_{22} \mathrm{ClNO}_{4}\), of mass 23.5 mg.

Vanadium forms four different oxides in which the percent by mass of vanadium is respectively (a) 76%, (b) 68%, (c) 61%, and (d) 56%. Determine the formula and the name of each one of these oxides

The chloride of an unknown metal is believed to have the formula MCl3 . A 2.395 g sample of the compound is found to contain 3.606 * 10-2 mol Cl . Find the atomic mass of M.

ain 3.606 * 10-2 mol Cl . Find the atomic mass of M. 138. Write the structural formulas of three different compounds that each have the molecular formula C5H12 .

A chromium-containing compound has the formula FexCryO4 and is 28.59% oxygen by mass. Find x and y .

A phosphorus compound that contains 34.00% phosphorus by mass has the formula X3P2 . Identify the element X.

A particular brand of beef jerky contains 0.0552% sodium nitrite by mass and is sold in an 8.00 oz bag. What mass of sodium does the sodium nitrite contribute to sodium content of the bag of beef jerky?

Phosphorus is obtained primarily from ores containing calcium phosphate. If a particular ore contains 57.8% calcium phosphate, what minimum mass of the ore must be processed to obtain 1.00 kg of phosphorus?

A mixture of NaCl and NaBr has a mass of 2.00 g and contains 0.75 g of Na. What is the mass of NaBr in the mixture?

Three pure compounds form when 1.00 g samples of element X combine with, respectively, 0.472 g, 0.630 g, and 0.789 g of element Z. The first compound has the formula X2Z3 . Find the empirical formulas of the other two compounds.

A mixture of CaCO3 and (NH4)2CO3 is 61.9% CO3 by mass. Find the mass percent of CaCO3 in the mixture.

A mixture of 50.0 g of S and 1.00 * 102 g of Cl2 reacts completely to form S2Cl2 and SCl2 . Find the mass of S2Cl2 formed.

Because of increasing evidence of damage to the ozone layer, chlorofluorocarbon (CFC) production was banned in 1996. However, there are about 100 million auto air conditioners in operation that still use CFC-12 \(\left(\mathrm{CF}_{2} \mathrm{Cl}_{2}\right)\). These air conditioners are recharged from stockpiled supplies of CFC-12. If each of the 100 million automobiles contains 1.1 kg of CFC-12 and leaks 25% of its CFC-12 into the atmosphere per year, how much chlorine, in kg, is added to the atmosphere each year due to auto air conditioners? (Assume two significant figures in your calculations.)

A particular coal contains 2.55% sulfur by mass. When the coal is burned, it produces SO2 emissions, which combine with rainwater to produce sulfuric acid. Use the formula of sulfuric acid to calculate the mass percent of S in sulfuric acid. Then determine how much sulfuric acid (in metric tons) is produced by the combustion of 1.0 metric ton of this coal. (A metric ton is 1000 kg.)

Lead is found in Earths crust as several different lead ores. Suppose a certain rock is 38.0% PbS (galena), 25.0% PbCO3 (cerussite), and 17.4% PbSO4 (anglesite). The remainder of the rock is composed of substances containing no lead. How much of this rock (in kg) must be processed to obtain 5.0 metric tons of lead? (A metric ton is 1000 kg.)

A 2.52 g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess O to yield 4.23 g of CO 2 and 1.01 g of H 2 O. Another sample of the same compound, of mass 4.14 g, yielded 2.11 g of SO 3 . A third sample, of mass 5.66 g, yielded 2.27 g of HNO 3 . Calculate the empirical formula of the compound.

A compound of molar mass 229 contains only carbon, hydrogen, iodine, and sulfur. Analysis shows that a sample of the compound contains 6 times as much carbon as hydrogen, by mass. Calculate the molecular formula of the compound.

he elements X and Y form a compound that is 40% X and 60% Y by mass. The atomic mass of X is twice that of Y. What is the empirical formula of the compound?

A compound of X and Y is 1 3 X by mass. The atomic mass of element X is 1 3 the atomic mass of element Y. Find the empirical formula of the compound.

A mixture of carbon and sulfur has a mass of 9.0 g. Complete combustion with excess O 2 gives 23.3 g of a mixture of CO 2 and SO 2 . Find the mass of sulfur in the original mixture.

When molecules are represented by molecular models, what does each sphere represent? How big is the nucleus of an atom in comparison to the sphere used to represent an atom in a molecular model?

Without doing any calculations, determine which element in each of the compounds will have the highest mass percent composition. a. CO b. N2O c. C6H12O6 d. NH

Explain the problem with the following statement and correct it. The chemical formula for ammonia (NH3) indicates that ammonia contains three grams of hydrogen to each gram of nitrogen.

Explain the problem with the following statement and correct it. When a chemical equation is balanced, the number of molecules of each type on both sides of the equation will be equal.

Without doing any calculations, arrange the elements in H2SO4 in order of decreasing mass percent composition.

Element A is an atomic element and element B is a diatomic molecular element. Using circles to represent atoms of A and squares to represent atoms of B, draw molecular level views of each element.