Solution: Oxidation-Reduction Reactions (Section)Determine

Which of the following schematic drawings best describes a solution of \(Li_2SO_4\) in water (water molecules not shown for simplicity)? [Section 4.1]

Aqueous solutions of three different substances, AX, AY, and AZ, are represented by the three accompanying diagrams. Identify each substance as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. [Section 4.1] + + + + + AX AY AZ (a) (b) (c)

Use the molecular representations shown here to classify each compound as a nonelectrolyte, a weak electrolyte, or a strong electrolyte (see Figure 4.6 for element color scheme). [Sections 4.1 and 4.3] (a) (b) (c)

The concept of chemical equilibrium is very important. Which one of the following statements is the most correct way to think about equilibrium? (a) If a system is at equilibrium, nothing is happening. (b) If a system is at equilibrium, the rate of the forward reaction is equal to the rate of the back reaction. (c) If a system is at equilibrium, the product concentration is changing over time. [Section 4.1]

You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next a Na2SO41aq2 solution is added and a white precipitate forms. What is the identity of the unknown white solid? [Section 4.2] Add Na2SO4(aq) Add H2O

We have seen that ions in aqueous solution are stabilized by the attractions between the ions and the water molecules. Why then do some pairs of ions in solution form precipitates? [Section 4.2]

Which of the following ions will always be a spectator ion in a precipitation reaction? (a) Cl -, (b) NO3 -, (c) NH4 +, (d) S2-, (e) SO4 2-. [Section 4.2]

The labels have fallen off three bottles containing powdered samples of metals; one contains zinc, one lead, and the other platinum. You have three solutions at your disposal: 1 M sodium nitrate, 1 M nitric acid, and 1 M nickel nitrate. How could you use these solutions to determine the identities of each metal powder? [Section 4.4

Explain how a redox reaction involves electrons in the same way that a neutralization reaction involves protons. [Sections 4.3 and 4.4]

If you want to double the concentration of a solution, how could you do it? [Section 4.5]

Which data set, of the two graphed here, would you expect to observe from a titration like that shown in Figure 4.18? [Section 4.6] 0 2 4 6 8 10 12 No color Highly colored mL standard solution Color from indicator

You are titrating an acidic solution with a basic one, and just realized you forgot to add the indicator that tells you when the equivalence point is reached. In this titration, the indicator turns blue at the equivalence point from an initially colorless solution. You quickly grab a bottle of indicator and throw some into your titration beaker, and the whole solution turns dark blue. What do you do now? [Section 4.6]

State whether each of the statements below is true or false. Justify your answer in each case. (a) Electrolyte solutions conduct electricity because electrons are moving through the solution. (b) If you add a nonelectrolyte to an aqueous solution that already contains an electrolyte, the electrical conductivity will not change.

State whether each of the statements below is true or false. Justify your answer in each case. (a) When methanol, CH3OH, is dissolved in water, a conducting solution results. (b) When acetic acid, CH3COOH, dissolves in water, the solution is weakly conducting and acidic in nature.

We have learned in this chapter that many ionic solids dissolve in water as strong electrolytes; that is, as separated ions in solution. Which statement is most correct about this process? (a) Water is a strong acid and therefore is good at dissolving ionic solids. (b) Water is good at solvating ions because the hydrogen and oxygen atoms in water molecules bear partial charges. (c) The hydrogen and oxygen bonds of water are easily broken by ionic solids.

Would you expect that anions would be physically closer to the oxygen or to the hydrogens of water molecules that surround it in solution?

Specify what ions are present in solution upon dissolving each of the following substances in water: (a) FeCl2, (b) HNO3, (c) 1NH422SO4, (d) Ca1OH22.

Specify what ions are present upon dissolving each of the following substances in water: (a) MgI2, (b) K2CO3, (c) HClO4, (d) NaCH3COO

Formic acid, HCOOH, is a weak electrolyte. What solutes are present in an aqueous solution of this compound? Write the chemical equation for the ionization of HCOOH.

Acetone, CH3COCH3, is a nonelectrolyte; hypochlorous acid, HClO, is a weak electrolyte; and ammonium chloride, NH4Cl, is a strong electrolyte. (a) What are the solutes present in aqueous solutions of each compound? (b) If 0.1 mol of each compound is dissolved in solution, which one contains 0.2 mol of solute particles, which contains 0.1 mol of solute particles, and which contains somewhere between 0.1 and 0.2 mol of solute particles?

Using solubility guidelines, predict whether each of the following compounds is soluble or insoluble in water: (a) MgBr2, (b) PbI2, (c) 1NH422CO3, (d) Sr1OH22, (e) ZnSO4.

Predict whether each of the following compounds is soluble in water: (a) AgI, (b) Na2CO3, (c) BaCl2, (d) Al1OH23, (e) Zn(CH3COO)2.

Will precipitation occur when the following solutions are mixed? If so, write a balanced chemical equation for the reaction. (a) Na2CO3 and AgNO3, (b) NaNO3 and NiSO4, (c) FeSO4 and Pb1NO322.

Identify the precipitate (if any) that forms when the following solutions are mixed, and write a balanced equation for each reaction. (a) NaCH3COO and HCl, (b) KOH and Cu1NO322, (c) Na2S and CdSO4.

Which ions remain in solution, unreacted, after each of the following pairs of solutions is mixed? (a) potassium carbonate and magnesium sulfate (b) lead nitrate and lithium sulfide (c) ammonium phosphate and calcium chloride

Write balanced net ionic equations for the reactions that occur in each of the following cases. Identify the spectator ion or ions in each reaction. (a) Cr21SO4231aq2 + 1NH422CO31aq2 (b) Ba1NO3221aq2 + K2SO41aq2 (c) Fe1NO3221aq2 + KOH1aq2

Separate samples of a solution of an unknown salt are treated with dilute solutions of HBr, H2SO4, and NaOH. A precipitate forms in all three cases. Which of the following cations could be present in the unknown salt solution: K+, Pb2+, Ba 2+?

Separate samples of a solution of an unknown ionic compound are treated with dilute AgNO3, Pb1NO322, and BaCl2. Precipitates form in all three cases. Which of the following could be the anion of the unknown salt: Br -, CO32-, NO3-?

You know that an unlabeled bottle contains an aqueous solution of one of the following: AgNO3, CaCl2, or Al21SO423. A friend suggests that you test a portion of the solution with Ba1NO322 and then with NaCl solutions. According to your friends logic, which of these chemical reactions could occur, thus helping you identify the solution in the bottle? (a) Barium sulfate could precipitate. (b) Silver chloride could precipitate. (c) Silver sulfate could precipitate. (d) More than one, but not all, of the reactions described in answers ac could occur. (e) All three reactions described in answers ac could occur.

Three solutions are mixed together to form a single solution; in the final solution, there are 0.2 mol Pb1CH3COO)2, 0.1 mol Na2S, and 0.1 mol CaCl2 present. What solid(s) will precipitate?

Which of the following solutions is the most acidic? (a) 0.2 M LiOH, (b) 0.2 M HI, (c) 1.0 M methyl alcohol 1CH3OH)

Which of the following solutions is the most basic? (a) 0.6 M NH3, (b) 0.150 M KOH, (c) 0.100 M Ba1OH22.

State whether each of the following statements is true or false. Justify your answer in each case. (a) Sulfuric acid is a monoprotic acid. (b) HCl is a weak acid. (c) Methanol is a base

State whether each of the following statements is true or false. Justify your answer in each case. (a) NH3 contains no OH- ions, and yet its aqueous solutions are basic. (b) HF is a strong acid. (c) Although sulfuric acid is a strong electrolyte, an aqueous solution of H2SO4 contains more HSO4 - ions than SO4 2- ions

Label each of the following substances as an acid, base, salt, or none of the above. Indicate whether the substance exists in aqueous solution entirely in molecular form, entirely as ions, or as a mixture of molecules and ions. (a) HF, (b) acetonitrile, CH3CN, (c) NaClO4, (d) Ba1OH22.

An aqueous solution of an unknown solute is tested with litmus paper and found to be acidic. The solution is weakly conducting compared with a solution of NaCl of the same concentration. Which of the following substances could the unknown be: KOH, NH3, HNO3, KClO2, H3PO3, CH3COCH3 (acetone)?

Classify each of the following substances as a nonelectrolyte, weak electrolyte, or strong electrolyte in water: (a) H2SO3, (b) C2H5OH (ethanol), (c) NH3, (d) KClO3, (e) Cu1NO322.

Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte: (a) LiClO4, (b) HClO, (c) CH3CH2CH2OH (propanol), (d) HClO3, (e) CuSO4, (f) C12H22O11 (sucrose).

Complete and balance the following molecular equations, and then write the net ionic equation for each: (a) HBr1aq2 + Ca1OH221aq2 (b) Cu1OH221s2 + HClO41aq2 (c) Al1OH231s2 + HNO31aq2

Write the balanced molecular and net ionic equations for each of the following neutralization reactions: (a) Aqueous acetic acid is neutralized by aqueous barium hydroxide. (b) Solid chromium(III) hydroxide reacts with nitrous acid. (c) Aqueous nitric acid and aqueous ammonia react

Write balanced molecular and net ionic equations for the following reactions, and identify the gas formed in each: (a) solid cadmium sulfide reacts with an aqueous solution of sulfuric acid; (b) solid magnesium carbonate reacts with an aqueous solution of perchloric acid.

Because the oxide ion is basic, metal oxides react readily with acids. (a) Write the net ionic equation for the following reaction: FeO1s2 + 2 HClO41aq2 Fe1ClO4221aq2 + H2O1l2 (b) Based on the equation in part (a), write the net ionic equation for the reaction that occurs between NiO(s) and an aqueous solution of nitric acid.

Magnesium carbonate, magnesium oxide, and magnesium hydroxide are all white solids that react with acidic solutions. (a) Write a balanced molecular equation and a net ionic equation for the reaction that occurs when each substance reacts with a hydrochloric acid solution. (b) By observing the reactions in part (a), how could you distinguish any of the three magnesium substances from the other two?

As K2O dissolves in water, the oxide ion reacts with water molecules to form hydroxide ions. (a) Write the molecular and net ionic equations for this reaction. (b) Based on the definitions of acid and base, what ion is the base in this reaction? (c) What is the acid in the reaction? (d) What is the spectator ion in the reaction?

True or false: (a) If a substance is oxidized, it is gaining electrons. (b) If an ion is oxidized, its oxidation number increases.

True or false: (a) Oxidation can occur without oxygen. (b) Oxidation can occur without reduction

(a) Which region of the periodic table shown here contains elements that are easiest to oxidize?

(b) Which region contains the least readily oxidized elements?

Determine the oxidation number of sulfur in each of the following substances: (a) barium sulfate, BaSO4, (b) sulfurous acid, H2SO3, (c) strontium sulfide, SrS, (d) hydrogen sulfide, H2S. (e) Locate sulfur in the periodic table in Exercise 4.47; what region is it in? (f) Which region(s) of the period table contains elements that can adopt both positive and negative oxidation numbers?

Determine the oxidation number for the indicated element in each of the following substances: (a) S in SO2, (b) C in COCl2, (c) Mn in KMnO4, (d) Br in HBrO, (e) P in PF3, (f) O in K2O2.

Determine the oxidation number for the indicated element in each of the following compounds: (a) Co in LiCoO2, (b) Al in NaAlH4, (c) C in CH3OH (methanol), (d) N in GaN, (e) Cl in HClO2, (f) Cr in BaCrO4.

Which element is oxidized and which is reduced in the following reactions? (a) N21g2 + 3 H21g2 2 NH31g2 (b) 3 Fe1NO3221aq2 + 2 Al1s2 3 Fe1s2 + 2 Al1NO3231aq2 (c) Cl21aq2 + 2 NaI1aq2 I21aq2 + 2 NaCl1aq2 (d) PbS1s2 + 4 H2O21aq2 PbSO41s2 + 4 H2O1l2

Which of the following are redox reactions? For those that are, indicate which element is oxidized and which is reduced. For those that are not, indicate whether they are precipitation or neutralization reactions. (a) P41s2 + 10 HClO1aq2 + 6 H2O1l2 4 H3PO41aq2 + 10 HCl1aq2 (b) Br21l) + 2 K1s2 2 KBr1s2 (c) CH3CH2OH1l2 + 3 O21g2 3 H2O1l2 + 2 CO21g2 (d) ZnCl21aq2 + 2 NaOH1aq2 Zn1OH221s2 + 2 NaCl1aq2

Write balanced molecular and net ionic equations for the reactions of (a) manganese with dilute sulfuric acid, (b) chromium with hydrobromic acid, (c) tin with hydrochloric acid, (d) aluminum with formic acid, HCOOH.

Write balanced molecular and net ionic equations for the reactions of (a) hydrochloric acid with nickel, (b) dilute sulfuric acid with iron, (c) hydrobromic acid with magnesium, (d) acetic acid, CH3COOH, with zinc.

Using the activity series (Table 4.5), write balanced chemical equations for the following reactions. If no reaction occurs, write NR. (a) Iron metal is added to a solution of copper(II) nitrate, (b) zinc metal is added to a solution of magnesium sulfate, (c) hydrobromic acid is added to tin metal, (d) hydrogen gas is bubbled through an aqueous solution of nickel(II) chloride, (e) aluminum metal is added to a solution of cobalt(II) sulfate.

Using the activity series (Table 4.5), write balanced chemical equations for the following reactions. If no reaction occurs, write NR. (a) Nickel metal is added to a solution of copper(II) nitrate, (b) a solution of zinc nitrate is added to a solution of magnesium sulfate, (c) hydrochloric acid is added to gold metal, (d) chromium metal is immersed in an aqueous solution of cobalt(II) chloride, (e) hydrogen gas is bubbled through a solution of silver nitrate

The metal cadmium tends to form Cd2+ ions. The following observations are made: (i) When a strip of zinc metal is placed in CdCl21aq), cadmium metal is deposited on the strip. (ii) When a strip of cadmium metal is placed in Ni1NO3221aq), nickel metal is deposited on the strip. (a) Write net ionic equations to explain each of the preceding observations. (b) Which elements more closely define the position of cadmium in the activity series? (c) What experiments would you need to perform to locate more precisely the position of cadmium in the activity series?

The following reactions (note that the arrows are pointing only one direction) can be used to prepare an activity series for the halogens: Br21aq2 + 2 NaI1aq2 2 NaBr1aq2 + I21aq2 Cl21aq2 + 2 NaBr1aq2 2 NaCl1aq2 + Br21aq2 (a) Which elemental halogen would you predict is the most stable, upon mixing with other halides? (b) Predict whether a reaction will occur when elemental chlorine and potassium iodide are mixed. (c) Predict whether a reaction will occur when elemental bromine and lithium chloride are mixed.

(a) Is the concentration of a solution an intensive or an extensive property?

(b) What is the difference between 0.50 mol HCl and 0.50 M HCl?

Your lab partner tells you that he has prepared a solution that contains 1.50 moles of NaOH in 1.50 L of aqueous solution, and therefore that the concentration of NaOH is 1.5 M. (a) Is he correct? (b) If not, what is the correct concentration?

(a) Calculate the molarity of a solution that contains 0.175 mol ZnCl2 in exactly 150 mL of solution.

(b) How many moles of protons are present in 35.0 mL of a 4.50 M solution of nitric acid? (c) How many milliliters of a 6.00 M NaOH solution are needed to provide 0.350 mol of NaOH?

(a) Calculate the molarity of a solution made by dissolving 12.5 grams of Na2CrO4 in enough water to form exactly 750 mL of solution.

(b) How many moles of KBr are present in 150 mL of a 0.112 M solution? (c) How many milliliters of 6.1 M HCl solution are needed to obtain 0.150 mol of HCl?

The average adult human male has a total blood volume of 5.0 L. If the concentration of sodium ion in this average individual is 0.135 M, what is the mass of sodium ion circulating in the blood?

A person suffering from hyponatremia has a sodium ion concentration in the blood of 0.118 M and a total blood volume of 4.6 L. What mass of sodium chloride would need to be added to the blood to bring the sodium ion concentration up to 0.138 M, assuming no change in blood volume?

The concentration of alcohol 1CH3CH2OH2 in blood, called the blood alcohol concentration or BAC, is given in units of grams of alcohol per 100 mL of blood. The legal definition of intoxication, in many states of the United States, is that the BAC is 0.08 or higher. What is the concentration of alcohol, in terms of molarity, in blood if the BAC is 0.08?

The average adult male has a total blood volume of 5.0 L. After drinking a few beers, he has a BAC of 0.10 (see Exercise 4.65). What mass of alcohol is circulating in his blood?

(a) How many grams of ethanol, CH3CH2OH, should you dissolve in water to make 1.00 L of vodka (which is an aqueous solution that is 6.86 M ethanol)?

(b) Using the density of ethanol (0.789 g/mL), calculate the volume of ethanol you need to make 1.00 L of vodka

One cup of fresh orange juice contains 124 mg of ascorbic acid (vitamin C, C6H8O6). Given that one cup = 236.6 mL, calculate the molarity of vitamin C in organic juice

(a) Which will have the highest concentration of potassium ion: 0.20 M KCl, 0.15 M K2CrO4, or 0.080 M K3PO4?

(b) Which will contain the greater number of moles of potassium ion: 30.0 mL of 0.15 M K2CrO4 or 25.0 mL of 0.080 M K3PO4?

In each of the following pairs, indicate which has the higher concentration of I - ion: (a) 0.10 M BaI2 or 0.25 M KI solution, (b) 100 mL of 0.10 M KI solution or 200 mL of 0.040 M ZnI2 solution, (c) 3.2 M HI solution or a solution made by dissolving 145 g of NaI in water to make 150 mL of solution.

Indicate the concentration of each ion or molecule present in the following solutions: (a) 0.25 M NaNO3, ( b ) 1.3 * 10-2 M MgSO4, ( c ) 0.0150 M C6H12O6, (d) a mixture of 45.0 mL of 0.272 M NaCl and 65.0 mL of 0.0247 M 1NH422CO3. Assume that the volumes are additive.

Indicate the concentration of each ion present in the solution formed by mixing (a) 42.0 mL of 0.170 M NaOH with 37.6 mL of 0.400 M NaOH, (b) 44.0 mL of 0.100 M Na2SO4 with 25.0 mL of 0.150 M KCl, (c) 3.60 g KCl in 75.0 mL of 0.250 M CaCl2 solution. Assume that the volumes are additive.

(a) You have a stock solution of 14.8 M NH3. How many milliliters of this solution should you dilute to make 1000.0 mL of 0.250 M NH3?

(b) If you take a 10.0-mL portion of the stock solution and dilute it to a total volume of 0.500 L, what will be the concentration of the final solution?

(a) How many milliliters of a stock solution of 6.0 M HNO3 would you have to use to prepare 110 mL of 0.500 M HNO3?

(b) If you dilute 10.0 mL of the stock solution to a final volume of 0.250 L, what will be the concentration of the diluted solution?

(a) Starting with solid sucrose, C12H22O11, describe how you would prepare 250 mL of a 0.250 M sucrose solution.

(b) Describe how you would prepare 350.0 mL of 0.100 M C12H22O11 starting with 3.00 L of 1.50 M C12H22O11.

(a) How many grams of solid silver nitrate would you need to prepare 200.0 mL of a 0.150 M AgNO3 solution?

(b) An experiment calls for you to use 100 mL of 0.50 M HNO3 solution. All you have available is a bottle of 3.6 M HNO3. How many milliliters of the 3.6 M HNO3 solution and of water do you need to prepare the desired solution?

Pure acetic acid, known as glacial acetic acid, is a liquid with a density of 1.049 g>mL at 25 C. Calculate the molarity of a solution of acetic acid made by dissolving 20.00 mL of glacial acetic acid at 25 C in enough water to make 250.0 mL of solution.

Glycerol, C3H8O3, is a substance used extensively in the manufacture of cosmetics, foodstuffs, antifreeze, and plastics. Glycerol is a water-soluble liquid with a density of 1.2656 g>mL at 15 C. Calculate the molarity of a solution of glycerol made by dissolving 50.000 mL glycerol at 15 C in enough water to make 250.00 mL of solution.

You want to analyze a silver nitrate solution. (a) You could add HCl(aq) to the solution to precipitate out AgCl(s). What volume of a 0.150 M HCl(aq) solution is needed to precipitate the silver ions from 15.0 mL of a 0.200 M AgNO3 solution? (b) You could add solid KCl to the solution to precipitate out AgCl(s). What mass of KCl is needed to precipitate the silver ions from 15.0 mL of 0.200 M AgNO3 solution? (c) Given that a 0.150 M HCl(aq) solution costs $39.95 for 500 mL, and that KCl costs $10/ton, which analysis procedure is more cost-effective?

You want to analyze a cadmium nitrate solution. What mass of NaOH is needed to precipitate the Cd2+ ions from 35.0 mL of 0.500 M Cd(NO322 solution?

(a) What volume of 0.115 M HClO4 solution is needed to neutralize 50.00 mL of 0.0875 M NaOH?

(b) What volume of 0.128 M HCl is needed to neutralize 2.87 g of Mg1OH22?

(c) If 25.8 mL of an AgNO3 solution is needed to precipitate all the Cl - ions in a 785-mg sample of KCl (forming AgCl), what is the molarity of the AgNO3 solution?

(d) If 45.3 mL of a 0.108 M HCl solution is needed to neutralize a solution of KOH, how many grams of KOH must be present in the solution?

(a) How many milliliters of 0.120 M HCl are needed to completely neutralize 50.0 mL of 0.101 M Ba1OH22 solution?

(b) How many milliliters of 0.125 M H2SO4 are needed to neutralize 0.200 g of NaOH?

(c) If 55.8 mL of a BaCl2 solution is needed to precipitate all the sulfate ion in a 752-mg sample of Na2SO4, what is the molarity of the BaCl2 solution?

(d) If 42.7 mL of 0.208 M HCl solution is needed to neutralize a solution of Ca1OH22, how many grams of Ca1OH22 must be in the solution?

Some sulfuric acid is spilled on a lab bench. You can neutralize the acid by sprinkling sodium bicarbonate on it and then mopping up the resultant solution. The sodium bicarbonate reacts with sulfuric acid according to: 2 NaHCO31s2 + H2SO41aq2 Na2SO41aq2 + 2 H2O1l2 + 2 CO21g2 Sodium bicarbonate is added until the fizzing due to the formation of CO21g2 stops. If 27 mL of 6.0 M H2SO4 was spilled, what is the minimum mass of NaHCO3 that must be added to the spill to neutralize the acid?

The distinctive odor of vinegar is due to acetic acid, CH3COOH, which reacts with sodium hydroxide according to: CH3COO1aq2 + NaOH1aq2 H2O1l2 + NaCH3OO1aq2 If 3.45 mL of vinegar needs 42.5 mL of 0.115 M NaOH to reach the equivalence point in a titration, how many grams of acetic acid are in a 1.00-qt sample of this vinegar?

A 4.36-g sample of an unknown alkali metal hydroxide is dissolved in 100.0 mL of water. An acidbase indicator is added and the resulting solution is titrated with 2.50 M HCl(aq) solution. The indicator changes color signaling that the equivalence point has been reached after 17.0 mL of the hydrochloric acid solution has been added. (a) What is the molar mass of the metal hydroxide? (b) What is the identity of the alkali metal cation: Li +, Na +, K+, Rb+, or Cs +?

An 8.65-g sample of an unknown group 2A metal hydroxide is dissolved in 85.0 mL of water. An acidbase indicator is added and the resulting solution is titrated with 2.50 M HCl(aq) solution. The indicator changes color signaling that the equivalence point has been reached after 56.9 mL of the hydrochloric acid solution has been added. (a) What is the molar mass of the metal hydroxide? (b) What is the identity of the metal cation: Ca 2+, Sr 2+, Ba 2+?

A solution of 100.0 mL of 0.200 M KOH is mixed with a solution of 200.0 mL of 0.150 M NiSO4. (a) Write the balanced chemical equation for the reaction that occurs. (b) What precipitate forms? (c) What is the limiting reactant? (d) How many grams of this precipitate form? (e) What is the concentration of each ion that remains in solution?

A solution is made by mixing 15.0 g of Sr1OH22 and 55.0 mL of 0.200 M HNO3. (a) Write a balanced equation for the reaction that occurs between the solutes. (b) Calculate the concentration of each ion remaining in solution. (c) Is the resultant solution acidic or basic?

A 0.5895-g sample of impure magnesium hydroxide is dissolved in 100.0 mL of 0.2050 M HCl solution. The excess acid then needs 19.85 mL of 0.1020 M NaOH for neutralization. Calculate the percentage by mass of magnesium hydroxide in the sample, assuming that it is the only substance reacting with the HCl solution.

A 1.248-g sample of limestone rock is pulverized and then treated with 30.00 mL of 1.035 M HCl solution. The excess acid then requires 11.56 mL of 1.010 M NaOH for neutralization. Calculate the percentage by mass of calcium carbonate in the rock, assuming that it is the only substance reacting with the HCl solution.

Uranium hexafluoride, UF6, is processed to produce fuel for nuclear reactors and nuclear weapons. UF6 is made from the reaction of elemental uranium with ClF3, which also produces Cl2 as a by- product. (a) Write the balanced molecular equation for the conversion of U and ClF3 into UF6 and Cl2. (b) Is this a metathesis reaction? (c) Is this a redox reaction?

The accompanying photo shows the reaction between a solution of Cd1NO322 and one of Na2S. (a) What is the identity of the precipitate? (b) What ions remain in solution? (c) Write the net ionic equation for the reaction. (d) Is this a redox reaction?

Suppose you have a solution that might contain any or all of the following cations: Ni 2+, Ag+, Sr 2+, and Mn2+. Addition of HCl solution causes a precipitate to form. After filtering off the precipitate, H2SO4 solution is added to the resulting solution and another precipitate forms. This is filtered off, and a solution of NaOH is added to the resulting solution. No precipitate is observed. Which ions are present in each of the precipitates? Which of the four ions listed above must be absent from the original solution?

You choose to investigate some of the solubility guidelines for two ions not listed in Table 4.1, the chromate ion 1CrO4 2-2 and the oxalate ion 1C2O4 2 - 2. You are given 0.01 M solutions (A, B, C, D) of four water-soluble salts: Solution Solute Color of Solution A Na2CrO4 Yellow B 1NH422C2O4 Colorless C AgNO3 Colorless D CaCl2 Colorless When these solutions are mixed, the following observations are made: (a) Write a net ionic equation for the reaction that occurs in each of the experiments. (b) Identify the precipitate formed, if any, in each of the experiments.

Antacids are often used to relieve pain and promote healing in the treatment of mild ulcers. Write balanced net ionic equations for the reactions between the aqueous HCl in the stomach and each of the following substances used in various antacids: (a) Al1OH231s2, (b) Mg1OH221s2, (c) MgCO31s2, (d) NaAl1CO3)1OH221s2, (e) CaCO31s2.

The commercial production of nitric acid involves the following chemical reactions: 4 NH31g2 + 5 O21g2 4 NO1g2 + 6 H2O1g2 2 NO1g2 + O21g2 2 NO21g2 3 NO21g2 + H2O1l2 2 HNO31aq2 + NO1g2 (a) Which of these reactions are redox reactions? (b) In each redox reaction identify the element undergoing oxidation and the element undergoing reduction. (c) How many grams of ammonia must you start with to make 1000.0 L of a 0.150 M aqueous solution of nitric acid? Assume all the reactions give 100% yield

Consider the following reagents: zinc, copper, mercury (density 13.6 g/mL), silver nitrate solution, nitric acid solution. (a) Given a 500-mL Erlenmeyer flask and a balloon, can you combine two or more of the foregoing reagents to initiate a chemical reaction that will inflate the balloon? Write a balanced chemical equation to represent this process. What is the identity of the substance that inflates the balloon? (b) What is the theoretical yield of the substance that fills the balloon? (c) Can you combine two or more of the foregoing reagents to initiate a chemical reaction that will produce metallic silver? Write a balanced chemical equation to represent this process. What ions are left behind in solution? (d) What is the theoretical yield of silver? 35.0 g Zn 42.0 g Cu 6.55 mL Hg 150 mL of 0.750 M AgNO3(aq) 150 mL of 3.00 M HNO3(aq)

Lanthanum metal forms cations with a charge of 3+. Consider the following observations about the chemistry of lanthanum: When lanthanum metal is exposed to air, a white solid (compound A) is formed that contains lanthanum and one other element. When lanthanum metal is added to water, gas bubbles are observed and a different white solid (compound B) is formed. Both A and B dissolve in hydrochloric acid to give a clear solution. When either of these solutions is evaporated, a soluble white solid (compound C) remains. If compound C is dissolved in water and sulfuric acid is added, a white precipitate (compound D) forms. (a) Propose identities for the substances A, B, C, and D. (b) Write net ionic equations for all the reactions described. (c) Based on the preceding observations, what can be said about the position of lanthanum in the activity series (Table 4.5)?

A 35.0-mL sample of 1.00 M KBr and a 60.0-mL sample of 0.600 M KBr are mixed. The solution is then heated to evaporate water until the total volume is 50.0 mL. How many grams of silver nitrate are required to precipitate out silver bromide in the final solution?

Using modern analytical techniques, it is possible to detect sodium ions in concentrations as low as 50 pg>mL. What is this detection limit expressed in (a) molarity of Na +, (b) the number of Na + ions per cubic centimeter of solution, (c) the mass of sodium per 1000 L of solution?

Hard water contains Ca 2+, Mg2+, and Fe 2+, which interfere with the action of soap and leave an insoluble coating on the insides of containers and pipes when heated. Water softeners replace these ions with Na +. Keep in mind that charge balance must be maintained. (a) If 1500 L of hard water contains 0.020 M Ca 2+ and 0.0040 M Mg2+, how many moles of Na + is needed to replace these ions? (b) If the sodium is added to the water softener in the form of NaCl, how many grams of sodium chloride are needed?

Tartaric acid, H2C4H4O6, has two acidic hydrogens. The acid is often present in wines and precipitates from solution as the wine ages. A solution containing an unknown concentration of the acid is titrated with NaOH. It requires 24.65 mL of 0.2500 M NaOH solution to titrate both acidic protons in 50.00 mL of the tartaric acid solution. Write a balanced net ionic equation for the neutralization reaction, and calculate the molarity of the tartaric acid solution

(a) A strontium hydroxide solution is prepared by dissolving 12.50 g of Sr1OH22 in water to make 50.00 mL of solution. What is the molarity of this solution?

(b) Next the strontium hydroxide solution prepared in part (a) is used to titrate a nitric acid solution of unknown concentration. Write a balanced chemical equation to represent the reaction between strontium hydroxide and nitric acid solutions.

(c) If 23.9 mL of the strontium hydroxide solution was needed to neutralize a 37.5 mL aliquot of the nitric acid solution, what is the concentration (molarity) of the acid?

A solid sample of Zn1OH22 is added to 0.350 L of 0.500 M aqueous HBr. The solution that remains is still acidic. It is then titrated with 0.500 M NaOH solution, and it takes 88.5 mL of the NaOH solution to reach the equivalence point. What mass of Zn1OH22 was added to the HBr solution?

Suppose you have 5.00 g of powdered magnesium metal, 1.00 L of 2.00 M potassium nitrate solution, and 1.00 L of 2.00 M silver nitrate solution. (a) Which one of the solutions will react with the magnesium powder? (b) What is the net ionic equation that describes this reaction? (c) What volume of solution is needed to completely react with the magnesium? (d) What is the molarity of the Mg2+ ions in the resulting solution?

(a) By titration, 15.0 mL of 0.1008 M sodium hydroxide is needed to neutralize a 0.2053-g sample of a weak acid. What is the molar mass of the acid if it is monoprotic?

(b) An elemental analysis of the acid indicates that it is composed of 5.89% H, 70.6% C, and 23.5% O by mass. What is its molecular formula?

A 3.455-g sample of a mixture was analyzed for barium ion by adding a small excess of sulfuric acid to an aqueous solution of the sample. The resultant reaction produced a precipitate of barium sulfate, which was collected by filtration, washed, dried, and weighed. If 0.2815 g of barium sulfate was obtained, what was the mass percentage of barium in the sample?

A fertilizer railroad car carrying 34,300 gallons of commercial aqueous ammonia (30% ammonia by mass) tips over and spills. The density of the aqueous ammonia solution is 0.88 g>cm3 . What mass of citric acid, C(OH21COOH21CH2COOH22, (which contains three acidic protons) is required to neutralize the spill? 1 gallon = 3.785 L

A sample of 7.75 g of Mg1OH22 is added to 25.0 mL of 0.200 M HNO3. (a) Write the chemical equation for the reaction that occurs. (b) Which is the limiting reactant in the reaction? (c) How many moles of Mg1OH22, HNO3, and Mg1NO322 are present after the reaction is complete?

Lead glass contains 1840% by mass of PbO (instead of CaO in regular glass). Lead glass is still used industrially, but lead crystal drinking goblets are no longer considered safe, as the lead may leach out and cause toxic responses in humans. A particular 286-g lead crystal goblet that holds 450 mL of liquid is 27% PbO by mass, and it leaches 3.4 micrograms of lead every time it is filled. How many grams of sodium sulfide would be required to decontaminate all the lead in the entire goblet?

The average concentration of gold in seawater is 100 fM (femtomolar). Given that the price of gold is $1764.20 per troy ounce (1 troy ounce = 31.103 g), how many liters of seawater would you need to process to collect $5000 worth of gold, assuming your processing technique captures only 50% of the gold present in the samples?

The mass percentage of chloride ion in a 25.00-mL sample of seawater was determined by titrating the sample with silver nitrate, precipitating silver chloride. It took 42.58 mL of 0.2997 M silver nitrate solution to reach the equivalence point in the titration. What is the mass percentage of chloride ion in seawater if its density is 1.025 g>mL?

The arsenic in a 1.22-g sample of a pesticide was converted to AsO4 3- by suitable chemical treatment. It was then titrated using Ag+ to form Ag3AsO4 as a precipitate. (a) What is the oxidation state of As in AsO4 3-? (b) Name Ag3AsO4 by analogy to the corresponding compound containing phosphorus in place of arsenic. (c) If it took 25.0 mL of 0.102 M Ag+ to reach the equivalence point in this titration, what is the mass percentage of arsenic in the pesticide?

The U.S. standard for arsenate in drinking water requires that public water supplies must contain no greater than 10 parts per billion (ppb) arsenic. If this arsenic is present as arsenate, AsO4 3-, what mass of sodium arsenate would be present in a 1.00-L sample of drinking water that just meets the standard? Parts per billion is defined on a mass basis as ppb = g solute g solution * 109

Federal regulations set an upper limit of 50 parts per million (ppm) of NH3 in the air in a work environment [that is, 50 molecules of NH31g2 for every million molecules in the air]. Air from a manufacturing operation was drawn through a solution containing 1.00 * 102 mL of 0.0105 M HCl. The NH3 reacts with HCl according to: NH31aq2 + HCl1aq2 NH4Cl1aq2 After drawing air through the acid solution for 10.0 min at a rate of 10.0 L>min, the acid was titrated. The remaining acid needed 13.1 mL of 0.0588 M NaOH to reach the equivalence point. (a) How many grams of NH3 were drawn into the acid solution? (b) How many ppm of NH3 were in the air? (Air has a density of 1.20 g>L and an average molar mass of 29.0 g>mol under the conditions of the experiment.) (c) Is this manufacturer in compliance with regulations?

Problem 1DE You are cleaning out a chemistry lab and find three unlabeled bottles, each containing white powder. Nearby these bottles are three loose labels: “Sodium sulfide,' “Sodium bicarbonate' and “Sodium chloride.' Let’s design an experiment to figure out which label goes with which bottle. (a) You could try to use the physical properties of the three solids to distinguish among them. Using an internet resource or the CRC Handbook of Chemistry and Physics, look up the melting points, aqueous solubilities, or other properties of these salts. Are the differences among these properties for each salt large enough to distinguish among them? If so, design a set of experiments todistinguish each salt and therefore figure out which label goes on which bottle. (b) You could use the chemical reactivity of each salt to distinguish it from the others. Which of these salts, if any, will act as an acid? A base? A strong electrolyte? Can any of these salts be easily oxidized or reduced? Can any of these salts react to produce a gas? Based on your answers to these questions, design a set of experiments to distinguish each salt and thus determine which label goes on which bottle.

Visualizing Concepts Which of the following schematic drawings best describes a solution of \(\mathrm{Li}_{2} \mathrm{SO}_{4}\) in water (water molecules not shown for simplicity)? [Section 4.1] Equation Transcription: Text Transcription: Li_{2}SO_4

Visualizing Concepts Aqueous solutions of three different substances, AX, AY, and AZ, are represented by the three accompanying diagrams. Identify each substance as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. [Section 4.1] Equation Transcription: Text Transcription: AX AY AZ AX AY AZ

Visualizing Concepts Use the molecular representations shown here to classify each compound as a nonelectrolyte, a weak electrolyte, or a strong electrolyte (see Figure 4.6 for element color scheme). [Sections 4.1 and 4.3]

Problem 4E Visualizing Concepts The concept of chemical equilibrium is very important. Which one of the following statements is the most correct way to think about equilibrium? (a) If a system is at equilibrium, nothing is happening. (b) If a system is at equilibrium, the rate of the forward reaction is equal to the rate of the back reaction. (c) If a system is at equilibrium, the product concentration is changing overtime. [Section]

Visualizing Concepts You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next a \(\mathrm{Na}_{2} \mathrm{SO}_{4}(a q)\) solution is added and a white precipitate forms. What is the identity of the unknown white solid? [Section 4.2] Equation Transcription: Text Transcription: Na_{2}SO_{4}(aq) H_{2}O Na_{2}SO_{4}(aq)

Problem 6E Visualizing Concepts We have seen that ions in aqueous solution are stabilized by the attractions between the ions and the water molecules. Why then do some pairs of ions in solution form precipitates? [Section]

Problem 7E Visualizing Concepts Which of the following ions will always be a spectator ion in a precipitation reaction?(a) CI-, (b) NO3- (c) NH4+, (d) S2-, (e) SO4 2-.[Section]

Problem 8E Visualizing Concepts The labels have fallen off three bottles containing powdered samples of metals; one contains zinc, one lead, and the other platinum. You have three solutions at your disposal: 1 M sodium nitrate, 1 M nitric acid, and 1 M nickel nitrate. How could you use these solutions to determine the identities of each metal powder? [Section]

Problem 9E Visualizing Concepts Explain how a redox reaction involves electrons in the same way that a neutralization reaction involves protons. [Sections]

Visualizing Concepts Which data set, of the two graphed here, would you expect to observe from a titration like that shown in Figure 4.18? [Section 4.6]

Problem 10E Visualizing Concepts If you want to double the concentration of a solution, how could you do it? [Section]

Problem 12E Visualizing Concepts You are titrating an acidic solution with a basic one, and just realized you forgot to add the indicator that tells you when the equivalence point is reached. In this titration, the indicator turns blue at the equivalence point from an initially colorless solution. You quickly grab a bottle of indicator and throw some into your titration beaker, and the whole solution turns dark blue. What do you do now? [Section]

Problem 13E General Properties of Aqueous Solutions (Section) State whether each of the statements below is true or false. Justify your answer in each case. (a) Electrolyte solutions conduct electricity because electrons are moving through the solution. (b) If you add a nonelectrolyte to an aqueous solution that already contains an electrolyte, the electrical conductivity will not change.

Problem 14E General Properties of Aqueous Solutions (Section) State whether each of the statements below is true or false. Justify your answer in each case. (a) When methanol, CH3OH, is dissolved in water, a conducting solution results. (b) When acetic acid, CH3COOH, dissolves in water, the solution is weakly conducting and acidic in nature.

Problem 15E General Properties of Aqueous Solutions (Section) We have learned in this chapter that many ionic solids dissolve in water as strong electrolytes; that is, as separated ions in solution. Which statement is most correct about this process? (a) Water is a strong acid and therefore is good at dissolving ionic solids, (b) Water is good at solvating ions because the hydrogen and oxygen atoms in water molecules bear partial charges, (c) The hydrogen and oxygen bonds of water are easily broken by ionic solids.

Problem 16E General Properties of Aqueous Solutions (Section) Would you expect that anions would be physically closer to the oxygen or to the hydrogens of water molecules that surround it in solution?

Problem 17E General Properties of Aqueous Solutions (Section) Specify what ions are present in solution upon dissolving each of the following substances in water: (a) FeCI2, (b) HNO3, (c) (NH4)2SO4, (d) Ca(OH)2.

Problem 19E General Properties of Aqueous Solutions (Section) Formic acid, HCOOH, is a weak electrolyte. What solutes are present in an aqueous solution of this compound? Write the chemical equation for the ionization of HCOOH

Problem 18E General Properties of Aqueous Solutions (Section) Specify what ions are present upon dissolving each of the following substances in water: (a) Mgl2, (b) K2CO3, (c) HCIO4, (d) NaCH3COO.

Problem 20E General Properties of Aqueous Solutions (Section) Acetone, CH3COCH3, is a nonelectrolyte; hypochlorous acid, HCIO, is a weak electrolyte; and ammonium chloride, NH4CI, is a strong electrolyte, (a) What are the solutes present in aqueous solutions of each compound? (b) If 0.1 mol of each compound is dissolved in solution, which one contains 0.2 mol of solute particles, which contains 0.1 mol of solute particles, and which contains somewhere between 0.1 and 0.2 mol of solute particles?

Problem 21E Precipitation Reactions (Section) Using solubility guidelines, predict whether each of the following compounds is soluble or insoluble in water: (a) MgBr2, (b) Pbl2, (c) (NH4)2CO3, (d) Sr(OH)2, (e) ZnSO4

Problem 22E Precipitation Reactions (Section) Predict whether each of the following compounds is soluble in water: (a) Agl, (b) Na2CO3, (c) BaCI2, (d) AI(OH)3, (e) Zn(CH3COO)2.

Problem 23E Precipitation Reactions (Section) Will precipitation occur when the following solutions are mixed? If so, write a balanced chemical equation for the reaction, (a) Na2CO3 and AgNO3, (b) NaNO3 and NiSO4, (c) FeSO4 and Pb(NO3)2.

Problem 24E Precipitation Reactions (Section) Identify the precipitate (if any) that forms when the following solutions are mixed, and write a balanced equation for each reaction, (a) NaCH3COO and HCI, (b) KOH and Cu(NO3)2, (c) Na2S and CdSO4.

Problem 25E Precipitation Reactions (Section) Which ions remain in solution, unreacted, after each of the following pairs of solutions is mixed? (a) potassium carbonate and magnesium sulfate (b) lead nitrate and lithium sulfide (c) ammonium phosphate and calcium chloride

Precipitation Reactions (Section 4.2) Write balanced net ionic equations for the reactions that occur in each of the following cases. Identify the spectator ion or ions in each reaction. (a) \(\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}(a q)+\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}(a q) \longrightarrow\) (b) \(\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}(a q)+\mathrm{K}_{2} \mathrm{SO}_{4}(a q) \longrightarrow\) (c) \(\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{2}(a q)+\mathrm{KOH}(a q) \longrightarrow\end{aligned}\) Equation Transcription: Text Transcription: Cr_{2}(SO_{4})_{3}(aq)+(NH_{4})_{2}CO_{3}(aq){rightarrow} Ba(NO_{3})_{2}(aq)+K_{2}SO_{4}(aq) Fe(NO_{3})(aq)+KOH(aq){rightarrow}

Problem 28E Precipitation Reactions (Section) Separate samples of a solution of an unknown ionic compound are treated with dilute AgNO3, Pb(NO3)2, and BaCI2.Precipitates form in all three cases. Which of the following could be the anion of the unknown salt: BrO, CO32-, NO3-?

Problem 27E Precipitation Reactions (Section) Separate samples of a solution of an unknown salt are treated with dilute solutions of HBr, H2SO4, and NaOH. A precipitate forms in all three cases. Which of the following cations could be present in the unknown salt solution: K+, Pb2+, Ba2+?

Problem 29E You know that an unlabeled bottle contains an aqueous solution of one of the following: AgNO3, CaCI2, or AI2(SO4)3. A friend suggests that you test a portion of the solution with Ba(NO3)2 and then with NaCI solutions. According to your friend's logic, which of these chemical reactions could occur, thus helping you identify the solution in the bottle? (a) Barium sulfate could precipitate, (b) Silver chloride could precipitate, (c) Silver sulphate could precipitate, (d) More than one, but not all, of the reactions described in answers a-c could occur, (e) All three reactions described in answers a-c could occur.

Problem 30E Precipitation Reactions (Section) Three solutions are mixed together to form a single solution; in the final solution, there are 0.2 mol Pb(CH3COO)2, 0.1 mol Na2S, and 0.1 mol CaCI2 present. What solid(s) will precipitate?

Problem 31E Acids, Bases, and Neutralization Reactions (Section) Which of the following solutions is the most acidic? (a) 0.2 MLiOH, (b) 0.2 MHI, (c) 1.0 M methyl alcohol (CH3OH).

Problem 33E Acids, Bases, and Neutralization Reactions (Section) State whether each of the following statements is true or false. Justify your answer in each case. (a) Sulfuric acid is a monoprotic acid. (b) HCI is a weak acid. (c) Methanol is a base.

Problem 32E Acids, Bases, and Neutralization Reactions (Section) Which of the following solutions is the most basic? (a) 0.6 MNH3, (b) 0.150 MKOH, (c) 0.100 MBa(OH)2.

Problem 35E Acids, Bases, and Neutralization Reactions (Section) Label each of the following substances as an acid, base, salt, or none of the above. Indicate whether the substance exists in aqueous solution entirely in molecular form, entirely as ions, or as a mixture of molecules and ions, (a) HF, (b) acetonitrile, CH3CN, (c) NaCIO4, (d) Ba(OH)2

Problem 34E Acids, Bases, and Neutralization Reactions (Section) State whether each of the following statements is true or false. Justify your answer in each case. (a) NH3 contains no OH- ions, and yet its aqueous solutions are basic. (b) HF is a strong acid. (c) Although sulfuric acid is a strong electrolyte, an aqueous solution of H2SO4 contains more HSO4- ions than SO42- ions.

Problem 36E Acids, Bases, and Neutralization Reactions (Section) An aqueous solution of an unknown solute is tested with litmus paper and found to be acidic. The solution is weakly conducting compared with a solution of NaCI of the same concentration. Which of the following substances could the unknown be: KOH, NH3, HNO3, KCIO2, H3PO3, CH3COCH3 (acetone)?

Problem 37E Acids, Bases, and Neutralization Reactions (Section) Classify each of the following substances as a nonelectrolyte.weak electrolyte, or strong electrolyte in water: (a) H2SO3, (b) C2H5OH (ethanol), (c) NH3, (d) KCIO3, (e) Cu(NO3)2.

Problem 38E Acids, Bases, and Neutralization Reactions (Section) Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte: (a) LiCIO4, (b) HCIO, (c) CH3CH2CH2OH (propanol), (d) HCIO3, (e) CuSO4, (f) C12H22O11 (sucrose).

Acids, Bases, and Neutralization Reactions (Section 4.3) Complete and balance the following molecular equations, and then write the net ionic equation for each: (a) \(\mathrm{HBr}(a q)+\mathrm{Ca}(\mathrm{OH})_{2}(a q) \longrightarrow\) (b) \(\mathrm{Cu}(\mathrm{OH})_{2}(s)+\mathrm{HClO}_{4}(a q) \longrightarrow\) (c) \(\mathrm{Al}(\mathrm{OH})_{3}(s)+\mathrm{HNO}_{3}(a q) \longrightarrow\) Equation Transcription: Text Transcription: HBr(aq)+Ca(OH)_{2}(aq){rightarrow} Cu(OH)_{2}(s)+HClO_{4}(aq){rightarrow} Al(OH)_{3}(s)+HNO_{3}(aq){rightarrow}

Problem 41E Acids, Bases, and Neutralization Reactions (Section) Write balanced molecular and net ionic equations for the following reactions, and identify the gas formed in each: (a) solid cadmium sulfide reacts with an aqueous solution of sulfuric acid (b) solid magnesium carbonate reacts with an aqueous solution of perchloric acid.

Problem 40E Acids, Bases, and Neutralization Reactions (Section) Write the balanced molecular and net ionic equations for each of the following neutralization reactions: (a) Aqueous acetic acid is neutralized by aqueous barium hydroxide. (b) Solid chromium(lll) hydroxide reacts with nitrous acid. (c) Aqueous nitric acid and aqueous ammonia react.

Acids, Bases, and Neutralization Reactions (Section 4.3) Because the oxide ion is basic, metal oxides react readily with acids. (a) Write the net ionic equation for the following reaction: \(\mathrm{FeO}(s)+2 \mathrm{HClO}_{4}(a q) \longrightarrow \mathrm{Fe}\left(\mathrm{ClO}_{4}\right)_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l)\) (b) Based on the equation in part (a), write the net ionic equation for the reaction that occurs between \(\mathrm {NiO}(s)\) and an aqueous solution of nitric acid. Equation Transcription: Text Transcription: FeO(s)+2 HClO4(aq)Fe(ClO4)2(aq)+H2O(l) NiO(s)

Problem 43E Acids, Bases, and Neutralization Reactions (Section) Magnesium carbonate, magnesium oxide, and magnesium hydroxide are all white solids that react with acidic solutions, (a) Write a balanced molecular equation and a net ionic equation for the reaction that occurs when each substance reacts with a hydrochloric acid solution, (b) By observing the reactions in part (a), how could you distinguish any of the three magnesium substances from the other two?

Problem 44E Acids, Bases, and Neutralization Reactions (Section) As K2O dissolves in water, the oxide ion reacts with water molecules to form hydroxide ions, (a) Write the molecular and net ionic equations for this reaction, (b) Based on the definitions of acid and base, what ion is the base in this reaction? (c) What is the acid in the reaction? (d) What is the spectator ion in the reaction?

Problem 45E Oxidation-Reduction Reactions (Section) True or false: (a) If a substance is oxidized, it is gaining electrons. (b) If an ion is oxidized, its oxidation number increases.

Problem 46E Oxidation-Reduction Reactions (Section) True or false: (a) Oxidation can occur without oxygen. (b) Oxidation can occur without reduction.

Oxidation-Reduction Reactions (Section 4.4) (a) Which region of the periodic table shown here contains elements that are easiest to oxidize? (b) Which region contains the least readily oxidized elements?

Problem 49E Oxidation-Reduction Reactions (Section) Determine the oxidation number for the indicated element in each of the following substances: (a) S in SO2, (b) C in COCI2, (c) Mn in KMnO4, (d) Br in HBrO, (e) P in PF3, (f) 0 in K2O2.

Problem 50E Oxidation-Reduction Reactions (Section) Determine the oxidation number for the indicated element in each of the following compounds: (a) Co in LiCoO2, (b) Alin NaAIH4, (c) C in CH3OH (methanol), (d) N in GaN, (e) Cl in HCIO2, (f) Cr in BaCr04.

Oxidation-Reduction Reactions (Section 4.4) Which element is oxidized and which is reduced in the following reactions? (a) \(\mathrm{N}_{2}(g)+3\ \mathrm{H}_{2}(g) \longrightarrow 2\ \mathrm{NH}_{3}(g)\) (b) \(3\ \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{Al}(s) \longrightarrow 3\ \mathrm {Fe}(s)+2\ \mathrm {Al(NO_3)_3}(aq)\) (c) \(\mathrm{Cl}_{2}(a q)+2\ \mathrm{NaI}(a q) \longrightarrow \mathrm{I}_{2}(a q)+2\ \mathrm{NaCl}(a q)\) (d) \(\mathrm{PbS}(s)+4\ \mathrm{H}_{2} \mathrm{O}_{2}(a q) \longrightarrow \mathrm{PbSO}_{4}(s)+4\ \mathrm{H}_{2} \mathrm{O}(l)\) Equation Transcription: Text Transcription: N_{2}(g)+3 H_{2}(g){rightarrow}2 NH_{3}(g) 3 Fe(NO_{3})_{2}(aq)+2 Al(s){rightarrow}3 Fe(s)+2 Al(NO_{3})_{3}(aq) Cl_{2}(aq)+2 NaI(aq){rightarrow}I_{2}(aq)+2 NaCl(aq) PbS(s)+4 H_{2}O_{2}(aq){rightarrow}PbSO_{4}(s)+4 H_{2}O(l)

Problem 53E Oxidation-Reduction Reactions (Section) Write balanced molecular and net ionic equations for the reactions of (a) manganese with dilute sulfuric acid, (b) chromium with hydrobromic acid, (c) tin with hydrochloric acid, (d) aluminum with formic acid, HCOOH.

Oxidation-Reduction Reactions (Section 4.4) Which of the following are redox reactions? For those that are, indicate which element is oxidized and which is reduced. For those that are not, indicate whether they are precipitation or neutralization reactions. (a) \(\mathrm{P}_{4}(s)+10\ \mathrm{HClO}(a q)+6\ \mathrm{H}_{2} \mathrm{O}(l) \longrightarrow 4\ \mathrm {H_3 PO_4}(aq)+10\ \mathrm {HCl}(aq)\) (b) \(\mathrm{Br}_{2}(l)+2 \mathrm{~K}(s) \longrightarrow 2\ \mathrm{KBr}(s)\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}(l)+3\ \mathrm{O}_{2}(g) \longrightarrow 3\ \mathrm{H}_{2} \mathrm{O}(l)+2\ \mathrm{CO}_{2}(g)\) (d) \(\mathrm{ZnCl}_{2}(a q)+2 \mathrm{NaOH}(a q) \longrightarrow \mathrm{Zn}(\mathrm{OH})_{2}(s)+ 2\ \mathrm {NaCl}(aq)\) Equation Transcription: Text Transcription: P_{4}(s)+10 HClO(aq)+6 H_{2}O(l){rightarrow}4 H_{3}PO_{4}(aq)+10 HCl(aq) Br_{2}(l)+2 K(s){rightarrow}2 Kbr(s) CH_{3}CH_{2}OH(l)+3 O_{2}(g){rightarrow}3 H_{2}O(l)+2 CO_{2}(g) ZnCl_{2}(aq)+2 NaOH(aq){rightarrow}Zn(OH)_{2}(s)+2 NaCl(aq)

Problem 54E Oxidation-Reduction Reactions (Section) Write balanced molecular and net ionic equations for the reactions of (a) hydrochloric acid with nickel, (b) dilute sulphuric acid with iron, (c) hydrobromic acid with magnesium, (d) acetic acid, CH3COOH, with zinc.

Oxidation-Reduction Reactions (Section 4.4) Using the activity series (Table 4.5), write balanced chemical equations for the following reactions. If no reaction occurs, write NR. (a) Iron metal is added to a solution of copper(II) nitrate, (b) zinc metal is added to a solution of magnesium sulfate, (c) hydrobromic acid is added to tin metal, (d) hydrogen gas is bubbled through an aqueous solution of nickel(II) chloride, (e) aluminum metal is added to a solution of cobalt(II) sulfate.

Oxidation-Reduction Reactions (Section 4.4) Using the activity series (Table 4.5), write balanced chemical equations for the following reactions. If no reaction occurs, write NR. (a) Nickel metal is added to a solution of copper(II) nitrate, (b) a solution of zinc nitrate is added to a solution of magnesium sulfate, (c) hydrochloric acid is added to gold metal, (d) chromium metal is immersed in an aqueous solution of cobalt(II) chloride, (e) hydrogen gas is bubbled through a solution of silver nitrate.

Problem 57E Oxidation-Reduction Reactions (Section) The metal cadmium tends to form Cd2+ ions. The following observations are made: (i) When a strip of zinc metal is placed in CdCI2(aq), cadmium metal is deposited on the strip, (ii) When a strip of cadmium metal is placed in Ni(NO3)2(aq), nickel metal is deposited on the strip, (a) Write net ionic equations to explain each of the preceding observations, (b) Which elements more closely define the position of cadmium in the activity series? (c) What experiments would you need to perform to locate more precisely the position of cadmium in the activity series?

Oxidation-Reduction Reactions (Section 4.4) The following reactions (note that the arrows are pointing only one direction) can be used to prepare an activity series for the halogens: \(\mathrm{Br}_{2}(a q)+2\ \mathrm{NaI}(a q) & \longrightarrow 2\ \mathrm{NaBr}(a q)+\mathrm{I}_{2}(a q)\) \(\mathrm{Cl}_{2}(a q)+2\ \mathrm{NaBr}(a q) & \longrightarrow 2\ \mathrm{NaCl}(a q)+\mathrm{Br}_{2}(a q)\) (a) Which elemental halogen would you predict is the most stable, upon mixing with other halides? (b) Predict whether a reaction will occur when elemental chlorine and potassium iodide are mixed. (c) Predict whether a reaction will occur when elemental bromine and lithium chloride are mixed. Equation Transcription: Text Transcription: Br_{2}(aq)+2 NaI(aq){rightarrow}2 NaBr(aq)+I_{2}(aq) Cl_{2}(aq)+2 NaBr(aq){rightarrow}2 NaCl(aq)+Br_{2}(aq)

Problem 59E Concentrations of Solutions (Section) (a) Is the concentration of a solution an intensive or an extensive property? (b) What is the difference between 0.50 mol HCI and 0.50 M HCI?

Problem 60E Concentrations of Solutions (Section) Your lab partner tells you that he has prepared a solution that contains 1.50 moles of NaOH in 1.50 L of aqueous solution, and therefore that the concentration of NaOH is 1.5 M. (a) Is he correct? (b) If not, what is the correct concentration?

Problem 61E Concentrations of Solutions (Section) (a) Calculate the molarity of a solution that contains 0.175 mol ZnCI2 in exactly 150 ml of solution, (b) How many moles of protons are present in 35.0 ml of a 4.50 M solution of nitric acid? (c) How many milliliters of a 6.00 M NaOH solution are needed to provide 0.350 mol of NaOH?

Problem 62E Concentrations of Solutions (Section) (a) Calculate the molarity of a solution made by dissolving 12.5 grams of Na2CrO4 in enough water to form exactly 750 ml of solution, (b) How many moles of KBr are present in 150 ml of a 0.112 M solution? (c) How many milliliters of 6.1 M HCI solution are needed to obtain 0.150 mol of HCI?

Problem 63E Concentrations of Solutions (Section) The average adult human male has a total blood volume of 5.0 L. If the concentration of sodium ion in this average individual is 0.135 M, what is the mass of sodium ion circulating in the blood?

Problem 64E Concentrations of Solutions (Section) A person suffering from hyponatremia has a sodium ion concentration in the blood of 0.118 M and a total blood volume of 4.6 L. What mass of sodium chloride would need to be added to the blood to bring the sodium ion concentration up to 0.138 M, assuming no change in blood volume?

Problem 65E Concentrations of Solutions (Section) The concentration of alcohol (CH3CH2OH) in blood, called the 'blood alcohol concentration' or BAC, is given in units of grams of alcohol per 100 ml of blood. The legal definition of intoxication, in many states of the United States, is that the BAC is 0.08 or higher. What is the concentration of alcohol, in terms of molarity, in blood if the BAC is 0.08?

Problem 66E Concentrations of Solutions (Section) The average adult male has a total blood volume of 5.0 L. After drinking a few beers, he has a BAC of 0.10 (see Exercise). What mass of alcohol is circulating in his blood? Exercise The concentration of alcohol (CH3CH2OH) in blood, called the 'blood alcohol concentration' or BAC, is given in units of grams of alcohol per 100 ml_ of blood. The legal definition of intoxication, in many states of the United States, is that the BAC is 0.08 or higher. What is the concentration of alcohol, in terms of molarity, in blood if the BAC is 0.08?

Problem 67E Concentrations of Solutions (Section) (a) How many grams of ethanol, CH3CH2OH, should you dissolve in water to make 1.00 L of vodka (which is an aqueous solution that is 6.86 Methanol)? (b) Using the density of ethanol (0.789 g/mL), calculate the volume of ethanol you need to make 1.00 L of vodka.

Problem 68E Concentrations of Solutions (Section) One cup of fresh orange juice contains 124 mg of ascorbic acid (vitamin C, C6H8O6). Given that one cup = 236.6 mL, calculate the molarity of vitamin C in organic juice.

Problem 69E Concentrations of Solutions (Section) (a) Which will have the highest concentration of potassium ion: 0.20 M KCI, 0.15 MK2CrO4, or 0.080 M K3PO4? (b) Which will contain the greater number of moles of potassium ion: 30.0 ml of 0.15 M K2CrO4 or 25.0 ml of 0.080 M K3PO4?

Problem 70E Concentrations of Solutions (Section) In each of the following pairs, indicate which has the higher concentration of I- ion: (a) 0.10 M Bal2 or 0.25 MKl solution, (b) 100 ml of 0.10 MKl solution or 200 ml of 0.040 M Znl2 solution, (c) 3.2 M HI solution or a solution made by dissolving 145 g of Nal in water to make 150 ml of solution.

Problem 71E Concentrations of Solutions (Section) Indicate the concentration of each ion or molecule present in the following solutions: (a) 0.25 MNaNO3, (b) 1.3 x 10-2 MMgSO4, (c) 0 . 0 1 5 0 MC6H12O6, (d) a mixture of45.0 ml of 0.272 M NaCI and 65.0 ml of 0.0247 M (NH4)2CO3. Assume that the volumes are additive.

Problem 72E Concentrations of Solutions (Section) Indicate the concentration of each ion present in the solution formed by mixing (a) 42.0 ml of 0.170 MNaOH with 37.6 ml of 0.400 MNaOH, (b) 44.0 ml of 0.100 MNa2S04 with 25.0 ml of 0.150 M KCI, (c) 3.60 g KCI in 75.0 ml of 0.250 M CaCI2 solution. Assume that the volumes are additive.

Problem 73E Concentrations of Solutions (Section) (a) You have a stock solution of 14.8 MNH3. How many millilitres of this solution should you dilute to make 1000.0 ml of 0.250 MNH3? (b) If you take a 10.0-mL portion of the stock solution and dilute it to a total volume of 0.500 L, what will be the concentration of the final solution?

Problem 75E Concentrations of Solutions (Section) (a) Starting with solid sucrose, C12H22O11, describe how you would prepare 250 ml of a 0.250 M sucrose solution, (b) Describe how you would prepare 350.0 ml of 0.100 M C12H22O11 starting with 3.00 L of 1.50 MC12H22O11.

Problem 74E Concentrations of Solutions (Section) (a) How many milliliters of a stock solution of 6.0 M HN03 would you have to use to prepare 110 ml of 0.500 MHNO3? (b) If you dilute 10.0 ml of the stock solution to a final volume of 0.250 L, what will be the concentration of the diluted solution?

Problem 77E Concentrations of Solutions (Section) Pure acetic acid, known as glacial acetic acid, is a liquid with a density of 1.049 g/mL at 25 °C. Calculate the molarity of a solution of acetic acid made by dissolving 20.00 ml of glacial acetic acid at 25 °C in enough water to make 250.0 ml of solution.

Problem 78E Concentrations of Solutions (Section) Glycerol, C3H8O3, is a substance used extensively in the manufacture of cosmetics, foodstuffs, antifreeze, and plastics. Glycerol is a water-soluble liquid with a density of 1.2656 g/mL at 15 °C. Calculate the molarity of a solution of glycerol made by dissolving 50.000 ml glycerol at 15 °C in enough water to make 250.00 ml of solution.

Problem 76E Concentrations of Solutions (Section) (a) How many grams of solid silver nitrate would you need to prepare 200.0 ml of a 0.150 M AgNO3 solution? (b) An experiment calls for you to use 100 ml of 0.50 M HNO3 solution. All you have available is a bottle of 3.6 MHNO3. How many milliliters of the 3.6 MHNO3 solution and of water do you need to prepare the desired solution?

Problem 79E Solution Stoichiometry and Chemical Analysis (Section) You want to analyze a silver nitrate solution, (a) You could add HCI(aq) to the solution to precipitate out AgCI(s). What volume of a 0.150 MHC\(aq) solution is needed to precipitate the silver ions from 15.0 ml of a 0.200 M AgN03 solution? (b) You could add solid KCI to the solution to precipitate out AgCI(s). What mass of KCI is needed to precipitate the silver ions from 15.0 ml of 0.200 M AgNO3 solution? (c) Given that a 0.150 MHC\(aq) solution costs $39.95 for 500 ml, and that KCI costs $10/ton, which analysis procedure is more cost-effective?

Problem 80E Solution Stoichiometry and Chemical Analysis (Section) You want to analyze a cadmium nitrate solution. What mass of NaOH is needed to precipitate the Cd2+ ions from 35.0 ml of 0.500 MCd(NO3)2 solution?

Problem 81E Solution Stoichiometry and Chemical Analysis (Section) (a)What volume of 0.115 MHCIO4 solution is needed to neutralize 50.00 ml of 0.0875 M NaOH? (b) What volume of 0.128 M HCI is needed to neutralize 2.87 g of Mg(OH)2? (c) If 25.8 ml of an AgNO3 solution is needed to precipitate all the Cl- ions in a 785-mg sample of KCI (forming AgCI), what is the molarity of the AgN03 solution? (d) If 45.3 ml of a 0.108 M HCI solution is needed to neutralize a solution of KOH, how many grams of KOH must be present in the solution?

Problem 82E Solution Stoichiometry and Chemical Analysis (Section) (a) How many milliliters of 0.120 M HCI are needed to completely neutralize 50.0 ml of 0.101 MBa(OH)2 solution? (b) How many milliliters of 0.125 MH2SO4 are needed to neutralize 0.200 g of NaOH? (c) If 55.8 ml of a BaCI2 solution is needed to precipitate all the sulfate ion in a 752-mg sample of Na2S04, what is the molarity of the BaCI2 solution? (d) If 42.7 ml of 0.208 M HCI solution is needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution?

Solution Stoichiometry and Chemical Analysis (Section 4.6) Some sulfuric acid is spilled on a lab bench. You can neutralize the acid by sprinkling sodium bicarbonate on it and then mopping up the resultant solution. The sodium bicarbonate reacts with sulfuric acid according to: \(2\ \mathrm{NaHCO}_{3}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}(a q)+ 2\ \mathrm{H}_{2} \mathrm{O}(l)+2\ \mathrm{CO}_{2}(g)\) Sodium bicarbonate is added until the fizzing due to the formation of \(\mathrm {CO_2}(g)\) stops. If 27 mL of \(6.0\ M\ \mathrm {H_2SO_4}\) was spilled, what is the minimum mass of \(\mathrm {NaHCO_3}\) that must be added to the spill to neutralize the acid? Equation Transcription: Text Transcription: 2 NaHCO_{3}(s)+H_{2}SO_{4}(aq){rightarrow}Na_{2}SO_{4}(aq)+2 H_{2}O(l)+2 CO_{2}(g) CO_{2}(g) 6.0 M H_{2}SO_{4} NaHCO_{3}

Solution Stoichiometry and Chemical Analysis (Section 4.6) The distinctive odor of vinegar is due to acetic acid, \(\mathrm {CH_3COOH}\), which reacts with sodium hydroxide according to: \(\mathrm{CH}_{3} \mathrm{COO}(a q)+\mathrm{NaOH}(a q) \longrightarrow{\mathrm{H}_{2} \mathrm{O}(l)}+\mathrm{NaCH}_{3} \mathrm{OO}(a q)\) If 3.45 mL of vinegar needs 42.5 mL of \(0.115\ M\ \mathrm {NaOH}\) to reach the equivalence point in a titration, how many grams of acetic acid are in a 1.00-qt sample of this vinegar? Equation Transcription: Text Transcription: CH_{3}COOH CH_{3}COO(aq) + NaOH(aq){rightarrow}H_{2}O(l) + NaCH_{3}OO(aq) 0.115 M NaOH

Problem 85E Solution Stoichiometry and Chemical Analysis (Section) A4.36-g sample of an unknown alkali metal hydroxide is dissolved in 100.0 ml of water. An acid-base indicator is added and the resulting solution is titrated with 2.50 M HCI(aq) solution. The indicator changes color signaling that the equivalence point has been reached after 17.0 ml of the hydrochloric acid solution has been added, (a) What is the molar mass ofthe metal hydroxide? (b) What is the identity of the alkali metal cation: Li+, Na+, K+, Rb+, or Cs+?

Problem 88E Solution Stoichiometry and Chemical Analysis (Section) A solution is made by mixing 15.0 g of Sr(OH)2 and 55.0 ml of 0.200 MHN03. (a) Write a balanced equation for the reaction that occurs between the solutes, (b) Calculate the concentration of each ion remaining in solution, (c) Is the resultant solution acidic or basic?

Problem 86E Solution Stoichiometry and Chemical Analysis (Section) An 8.65-g sample of an unknown group 2A metal hydroxide is dissolved in 85.0 ml of water. An acid-base indicator is added and the resulting solution is titrated with 2.50 M HCI(ag) solution. The indicator changes color signaling that the equivalence point has been reached after 56.9 ml of the hydrochloric acid solution has been added (a) What is the molar mass of the metal hydroxide? (b) What is the identity of the metal cation: Ca2+, Sr2+, Ba2+?

Problem 87E Solution Stoichiometry and Chemical Analysis (Section) A solution of 100.0 ml of 0.200 M KOH is mixed with a solution of 200.0 ml of 0.150 M NiS04. (a) Write the balanced chemical equation for the reaction that occurs, (b) What precipitate forms? (c) What is the limiting reactant? (d) How many grams of this precipitate form? (e) What is the concentration of each ion that remains in solution?

Problem 89E Stoichiometry and Chemical Analysis (Section) A 0.5895-g sample of impure magnesium hydroxide is dissolved in 100.0 ml of 0.2050 MHCl solution. The excess acid then needs 19.85 ml of 0.1020 MNaOH for neutralization. Calculate the percentage by mass of magnesium hydroxide in the sample, assuming that it is the only substance reacting with the HCI solution.

Problem 90E Stoichiometry and Chemical Analysis (Section) A 1.248-g sample of limestone rock is pulverized and then treated with 30.00 ml of 1.035 M HCI solution. The excess acid then requires 11.56 ml of 1.010 MNaOH for neutralization. Calculate the percentage by mass of calcium carbonate in the rock, assuming that it is the only substance reacting with the HCI solution.

Problem 91AE Uranium hexafluoride, UF6, is processed to produce fuel for nuclear reactors and nuclear weapons. UF6 is made from the reaction of elemental uranium with CIF3, which also produces CI2 as a by-product. (a) Write the balanced molecular equation for the conversion of U and CIF3 into UF6 and CI2. (b) Is this a metathesis reaction? (c) Is this a redox reaction?

The accompanying photo shows the reaction between a solution of \(\mathrm {Cd(NO_3)_2}\) and one of \(\mathrm {Na_2S}\). (a) What is the identity of the precipitate? (b) What ions remain in solution? (c) Write the net ionic equation for the reaction. (d) Is this a redox reaction? Equation Transcription: Text Transcription: Cd(NO_3)_2 Na_{2}S

Problem 93AE Suppose you have a solution that might contain any or all of the following cations: Ni2+, Ag+ Sr2+, and Mn2+. Addition of HCI solution causes a precipitate to form. After filtering off the precipitate, H2S04 solution is added to the resulting solution and another precipitate forms. This is filtered off, and a solution of NaOH is added to the resulting solution. No precipitate is observed. Which ions are present in each of the precipitates? Which of the four ions listed above must be absent from the original solution?

You choose to investigate some of the solubility guidelines for two ions not listed in Table 4.1, the chromate ion \(\left(\mathrm{CrO}_{4}^{2-}\right)\) and the oxalate ion \(\left(\mathrm{C}_{2} \mathrm{O}_{4}{ }^{2-}\right)\). You are given 0.01 M solutions (A, B, C, D) of four water-soluble salts: Solution Solute Color of Solution A \(\mathrm{Na}_{2} \mathrm{CrO}_{4}\) Yellow B \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{C}_{2} \mathrm{O}_{4}\) Colorless C \(\mathrm{AgNO}_{3}\) Colorless D \(\mathrm{CaCl}_{2}\) Colorless When these solutions are mixed, the following observations are made: (a) Write a net ionic equation for the reaction that occurs in each of the experiments. (b) Identify the precipitate formed, if any, in each of the experiments. Equation Transcription: Text Transcription: (CrO_4^2-) (C_2O_4^2-) Na_2CrO_4 (NH_4)_2C_2O_4 AgNO_3 CaCl_2

Problem 95AE Antacids are often used to relieve pain and promote healing in the treatment of mild ulcers. Write balanced net ionic equations for the reactions between the aqueous HCI in the stomach and each of the following substances used in various antacids: (a) AI(OH)3(s), (b) Mg(OH)2(s), (c) MgCO3(s), (d) NaAI(CO3)(OH)2(s), (e) CaCO3(s).

The commercial production of nitric acid involves the following chemical reactions: \(4\ \mathrm{NH}_{3}(g)+5\ \mathrm{O}_{2}(g) & \longrightarrow 4\ \mathrm{NO}(g)+6 \mathrm{H}_{2} \mathrm{O}(g)\) \(2\ \mathrm{NO}(g)+\mathrm{O}_{2}(g) & \longrightarrow 2\ \mathrm{NO}_{2}(g)\) \(3\ \mathrm{NO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l) & \longrightarrow 2\ \mathrm{HNO}_{3}(a q)+\mathrm{NO}(g)\) (a) Which of these reactions are redox reactions? (b) In each redox reaction identify the element undergoing oxidation and the element undergoing reduction. (c) How many grams of ammonia must you start with to make of a aqueous solution of nitric acid? Assume all the reactions give yield. Equation Transcription: Text Transcription: 4 NH_3(g)+5 O_2(g){rightarrow}4 NO(g)+6 H_2O(g) 2 NO(g)+O_2(g){rightarrow}2 NO_2(g) 3 NO_2(g)+H_2O(l){rightarrow}2 HNO_3(aq)+NO(g)

Consider the following reagents: zinc, copper, mercury (density 13.6 g/mL), silver nitrate solution, nitric acid solution. (a) Given a 500-mL Erlenmeyer flask and a balloon, can you combine two or more of the foregoing reagents to initiate a chemical reaction that will inflate the balloon? Write a balanced chemical equation to represent this process. What is the identity of the substance that inflates the balloon? (b) What is the theoretical yield of the substance that fills the balloon? (c) Can you combine two or more of the foregoing reagents to initiate a chemical reaction that will produce metallic silver? Write a balanced chemical equation to represent this process. What ions are left behind in solution? (d) What is the theoretical yield of silver? Equation Transcription: Text Transcription: 13.6 g/mL 35.0 g Zn 42.0 g Cu 6.55 mL Hg 0.750 M AgNO_3(aq) 3.00 M HNO_3(aq)

Lanthanum metal forms cations with a charge of 3+. Consider the following observations about the chemistry of lanthanum: When lanthanum metal is exposed to air, a white solid (compound A) is formed that contains lanthanum and one other element. When lanthanum metal is added to water, gas bubbles are observed and a different white solid (compound B) is formed. Both A and B dissolve in hydrochloric acid to give a clear solution. When either of these solutions is evaporated, a soluble white solid (compound C) remains. If compound C is dissolved in water and sulfuric acid is added, a white precipitate (compound D) forms. (a) Propose identities for the substances A, B, C, and D. (b) Write net ionic equations for all the reactions described. (c) Based on the preceding observations, what can be said about the position of lanthanum in the activity series (Table 4.5)?

Problem 99AE A 35.0-mL sample of 1.00 M KBr and a 60.0-mL sample of 0.600 M KBr are mixed. The solution is then heated to evaporate water until the total volume is 50.0 ml. How many grams of silver nitrate are required to precipitate out silver bromide in the final solution?

Problem 100AE Using modern analytical techniques, it is possible to detect sodium ions in concentrations as low as 50 pg/mL. What is this detection limit expressed in (a) molarity of Na+, (b) the number of Na+ ions per cubic centimeter of solution, (c) the mass of sodium per 1000 L of solution?

Problem 101AE Hard water contains Ca2+, Mg2+, and Fe2+, which interfere with the action of soap and leave an insoluble coating on the insides of containers and pipes when heated. Water softeners replace these ions with Na+. Keep in mind that charge balance must be maintained, (a) If 1500 L of hard water contains 0.020 M Ca2+ and 0.0040 M Mg2+, how many moles of Na+ is needed to replace these ions? (b) If the sodium is added to the water softener in the form of NaCI, how many grams of sodium chloride are needed?

Problem 102AE Tartaric acid, H2C4H406, has two acidic hydrogens. The acid is often present in wines and precipitates from solution as the wine ages. A solution containing an unknown concentration of the acid is titrated with NaOH. It requires 24.65 ml of 0.2500 MNaOH solution to titrate both acidic protons in 50.00 ml of the tartaric acid solution. Write a balanced net ionic equation for the neutralization reaction, and calculate the molarity of the tartaric acid solution.

Problem 103AE (a) A strontium hydroxide solution is prepared by dissolving 12.50 g of Sr(OH)2 in water to make 50.00 ml of solution. What is the molarity of this solution? (b) Next the strontium hydroxide solution prepared in part (a) is used to titrate a nitric acid solution of unknown concentration. Write a balanced chemical equation to represent the reaction between strontium hydroxide and nitric acid solutions, (c) If 23.9 ml of the strontium hydroxide solution was needed to neutralize a 37.5 ml aliquot of the nitric acid solution, what is the concentration (molarity) of the acid?

Problem 104AE A solid sample of Zn(OH)2 is added to 0.350 L of 0.500 M aqueous HBr. The solution that remains is still acidic. It is then titrated with 0.500 MNaOH solution, and it takes 88.5 ml of the NaOH solution to reach the equivalence point. What mass of Zn(OH)2 was added to the HBr solution?

Problem 105IE Suppose you have 5.00 g of powdered magnesium metal, 1.00 L of 2.00 M potassium nitrate solution, and 1.00 L of 2.00 M silver nitrate solution, (a) Which one of the solutions will react with the magnesium powder? (b) What is the net ionic equation that describes this reaction? (c) What volume of solution is needed to completely react with the magnesium? (d) What is the molarity of the Mg2+ ions in the resulting solution?

Problem 106IE (a) By titration, 15.0 ml of 0.1008 M sodium hydroxide is needed to neutralize a 0.2053-g sample of a weak acid. What is the molar mass of the acid if it is monoprotic? (b) An elemental analysis of the acid indicates that it is composed of 5.89% H, 70.6% C, and 23.5% O by mass. What is its molecular formula?

Problem 107IE A 3.455-g sample of a mixture was analyzed for barium ion by adding a small excess of sulfuric acid to an aqueous solution of the sample. The resultant reaction produced a precipitate of barium sulfate, which was collected by filtration, washed, dried, and weighed. If 0.2815 g of barium sulfate was obtained, what was the mass percentage of barium in the sample?

Problem 109IE A sample of 7.75 g of Mg(OH)2 is added to 25.0 ml of 0.200 M HN03. (a) Write the chemical equation for the reaction that occurs, (b) Which is the limiting reactant in the reaction? (c) How many moles of Mg(OH)2, HN03, and Mg(N03)2 are present after the reaction is complete?

Problem 108IE A fertilizer railroad car carrying 34,300 gallons of commercial aqueous ammonia (30% ammonia by mass) tips over and spills. The density of the aqueous ammonia solution is 0.88 g/cm3. What mass of citric acid, C(OH)(COOH)(CH2COOH)2, (which contains three acidic protons) is required to neutralize the spill? 1 gallon = 3.785 L.

Problem 110IE Lead glass contains 18-40% by mass of PbO (instead of CaO in regular glass). Lead glass is still used industrially, but lead crystal' drinking goblets are no longer considered safe, as the lead may leach out and cause toxic responses in humans. A particular 286-g lead crystal goblet that holds 450 mL of liquid is 27% PbO by mass, and it leaches 3.4 micrograms of lead every time it is filled. How many grams of sodium sulfide would be required to decontaminate all the lead in the entire goblet?

Problem 48E Oxidation-Reduction Reactions (Section) Determine the oxidation number of sulfur in each of the following substances: (a) barium sulfate, BaSO4, (b) sulfurous acid, H2SO3, (c) strontium sulfide, SrS, (d) hydrogen sulfide, H2S. (e) Locate sulfur in the periodic table in Exercise 4.47; what region is it in? (f) Which region(s) of the period table contains elements that can adopt both positive and negative oxidation numbers?

Federal regulations set an upper limit of 50 parts per million (ppm) of \(N H_{3}\) in the air in a work environment [that is, 50 molecules of \(N H_{3}\)(g) for every million molecules in the air]. Air from a manufacturing operation was drawn through a solution containing \(\text { 1. } 00 \times 10^{2} m L\) of 0.0105 M HCl. The \(N H_{3}\) reacts with HCl according to: \(\mathrm{NH}_{3}(a q)+\mathrm{HCI}(a q) \rightarrow \mathrm{NH}_{4} \mathrm{CI}(a q)\) After drawing air through the acid solution for 10.0 min at a rate of 10.0 L/min, the acid was titrated. The remaining acid needed 13.1 mL of 0.0588 M NaOH to reach the equivalence point. (a) How many grams of NH3 were drawn into the acid solution? (b) How many ppm of NH3 were in the air? (Air has a density of 1.20 g/L and an average molar mass of 29.0 g/mol under the conditions of the experiment.) (c) Is this manufacturer in compliance with regulations? Equation transcription: Text transcription: N H_{3} \text { 1. } 00 times 10^{2} m L {NH}_{3}(a q)+{HCI}(a q) rightarrow {NH}_{4}{CI}(a q)

The U.S. standard for arsenate in drinking water requires that public water supplies must contain no greater than 10 parts per billion (ppb) arsenic. If this arsenic is present as arsenate, \(\mathrm{AsO}_{4}^{3-}\), what mass of sodium arsenate would be present in a 1.00-L sample of drinking water that just meets the standard? Parts per billion is defined on a mass basis as \(p p b=\frac{\text { gsolute }}{\text { gsolution }} \times 10^{9}\) Equation transcription: Text transcription: \mathrm{AsO}_{4}^{3-} p p b=\frac{\text { gsolute }}{\text { gsolution }} \times 10^{9}

Problem 112IE The mass percentage of chloride ion in a 25.00-mL sample of seawater was determined by titrating the sample with silver nitrate, precipitating silver chloride. It took 42.58 ml of 0.2997 M silver nitrate solution to reach the equivalence point in the titration. What is the mass percentage of chloride ion in seawater if its density is 1.025 g/ml?

Problem 113IE The arsenic in a 1.22-g sample of a pesticide was converted to As043- by suitable chemical treatment. It was then titrated using Ag+ to form Ag3As04 as a precipitate, (a) What is the oxidation state of As in As043-? (b) Name Ag3As04 by analogy to the corresponding compound containing phosphorus in place of arsenic, (c) If it took 25.0 ml of 0.102 M Ag+ to reach the equivalence point in this titration, what is the mass percentage of arsenic in the pesticide?

Problem 111IE The average concentration of gold in seawater is 100 fM (femtomolar). Given that the price of gold is $1764.20 per troy ounce (1 troy ounce = 31.103 g), how many liters of seawater would you need to process to collect $5000 worth of gold, assuming your processing technique captures only 50% of the gold present in the samples?