Why is moist air less dense than dry air?

Problem 1P How does a sample of gas differ in its behavior from a sample of liquid in each of the following situations? (a) The sample is transferred from one container to a larger one. ________________ (b) The sample is heated in an expandable container, but no change of state occurs. ________________ (c) The sample is placed in a cylinder with a piston, and an external force is applied.

Problem 5P On a cool, rainy day, the barometric pressure is 730 mmHg. Calculate the barometric pressure in centimeters of water (cmH2O) (d of Hg = 13.5 g/mL; d of H2O = 1.00 g/mL).

Problem 6P A long glass tube, sealed at one end, has an inner diameter of 10.0 mm. The tube is filled with water and inverted into a pail of water. If the atmospheric pressure is 755 mmHg, how high (in mmH2O) is the column of water in the tube (d of Hg = 13.5 g/mL; d of H2O = 1.00 g/mL)?

Problem 2P Are the particles in a gas farther apart or closer together than the particles in a liquid? Use your answer to explain each of the following general observations: (a) Gases are more compressible than liquids. ________________ (b) Gases have lower viscosities than liquids. ________________ (c) After thorough stirring, all gas mixtures are solutions. ________________ (d) The density of a substance in the gas state is lower than in the liquid state.

Problem 11P A student states Boyle’s law as follows: “The volume of a gas is inversely proportional to its pressure.” How is this statement incomplete? Give a correct statement of Boyle’s law.

Problem 8P Convert the following: (a) 76.8 cmHg to atm (b) 27.5 atm to kPa (c) 6.50 atm to bar (d) 0.937 kPa to torr

Problem 7P Convert the following: (a) 0.745 atm to mmHg (b) 992 torr to bar (c) 365 kPa to atm (d) 804 mmHg to kPa

Problem 13P Boyle’s law relates gas volume to pressure, and Avogadro’s law relates gas volume to number of moles. State a relationship between gas pressure and number of moles.

Problem 10P The gravitational force exerted by an object is given by F = mg, where F is the force in newtons, m is the mass in kilograms, and g is the acceleration due to gravity (9.81 m/s2). (a) Use the definition of the pascal to calculate the mass (in kg) of the atmosphere above 1 m2 of ocean. ________________ (b) Osmium (Z = 76) is a transition metal in Group 8B(8) and has the highest density of any element (22.6 g/mL). If an osmium column is 1 m2 in area, how high must it be for its pressure to equal atmospheric pressure? [Use the answer from part (a) in your calculation.]

Each of the following processes caused the gas volume to double, as illustrated. For each process, state how the remaining gas variable changed or that it remained fixed: (a) T doubles at fixed P. (b) T and n are fixed.

Problem 9P Convert each of the pressures described below to atm: (a) At the peak of Mt. Everest, atmospheric pressure is only 2.75 X 102 mmHg. ________________ (b) A cyclist fills her bike tires to 86 psi. ________________ (c) The surface of Venus has an atmospheric pressure of 9.15 X 106 Pa. ________________ (d) At 100 ft below sea level, a scuba diver experiences a pressure of 2.54 X 104 torr.

Problem 15P What is the effect of the following on the volume of 1 mol of an ideal gas? (a) The pressure is tripled (at constant T). ________________ (b) The absolute temperature is increased by a factor of 3.0 (at constant P). ________________ (c) Three more moles of the gas are added (at constant P and T).

Problem 17P A sample of sulfur hexafluoride gas occupies 9.10 L at 198°C. Assuming that the pressure remains constant, what temperature (in °C) is needed to reduce the volume to 2.50 L?

Problem 18P A 93-L sample of dry air cools from 145°C to ?22°C while the pressure is maintained at 2.85 atm. What is the final volume?

Problem 16P What is the effect of the following on the volume of 1 mol of an ideal gas? (a) The pressure is reduced by a factor of 4 (at constant T). ________________ (b) The pressure changes from 760 torr to 202 kPa, and the temperature changes from 37°C to 155 K. ________________ (c) The temperature changes from 305 K to 32°C, and the pressure changes from 2 atm to 101 kPa.

Problem 19P A sample of Freon-12 (CF2Cl2) occupies 25.5 L at 298 K and 153.3 kPa. Find its volume at STP.

Problem 20P A sample of carbon monoxide occupies 3.65 L at 298 K and 745 torr. Find its volume at - 14°C and 367 torr.

Problem 22P If 1.47 X 10-3 mol of argon occupies a 75.0-mL container at 26°C, what is the pressure (in torr)?

Problem 23P You have 357 mL of chlorine trifiuoride gas at 699 mmHg and 45°C. What is the mass (in g) of the sample?

Problem 21P A sample of chlorine gas is confined in a 5.0-L container at 328 torr and 37°C. How many moles of gas are in the sample?

Problem 24P A 75.0-g sample of dinitrogen monoxide is confined in a 3.1-L vessel. What is the pressure (in atm) at 115°C?

Problem 25P In preparation for a demonstration, your professor brings a 1.5-L bottle of sulfur dioxide into the lecture hall before class to allow the gas to reach room temperature. If the pressure gauge reads 85 psi and the temperature in the hall is 23°C, how many moles of sulfur dioxide are in the bottle? (Hint: The gauge reads zero when 14.7 psi of gas remains.)

Problem 27P To collect a beaker of H2 gas by displacing the air already in the beaker, would you hold the beaker upright or inverted? Why? How would you hold the beaker to collect CO2?

Problem 28P Why can we use a gas mixture, such as air, to study the general behavior of an ideal gas under ordinary conditions?

Problem 26P Why is moist air less dense than dry air?

Problem 29P How does the partial pressure of gas A in a mixture compare to its mole fraction in the mixture? Explain.

The circle at right depicts a portion of a mixture of four gases: A (purple), B (brown), C (green), and D2 (orange). (a) Which has the highest partial pressure? (b) Which has the lowest partial pressure? (c) If the total pressure is \(0.75 atm\), what is the partial pressure of \(\mathrm{D}_{2}\)? Equation Transcription: D2 Text Transcription: 0.75 atm D_2

Problem 33P How many moles of gaseous arsine (AsH3) occupy 0.0400 L at STP? What is the density of gaseous arsine?

Problem 31P What is the density of Xe gas at STP?

Problem 34P The density of a noble gas is 2.71 g/L at 3.00 atm and 0°C. Identify the gas.

What is the density of Freon-11 \(\left(\mathrm{CFCl}_{3}\right)\) at \(120^{\circ} \mathrm{C}\) and \(1.5 \mathrm{~atm}\)?

Problem 35P Calculate the molar mass of a gas at 388 torr and 45°C if 206 ng occupies 0.206 µL.

Problem 36P When an evacuated 63.8-mL glass bulb is filled with a gas at 22°C and 747 mmHg, the bulb gains 0.103 g in mass. Is the gas N2. Ne. or Ar?

Problem 37P After 0.600 L of Ar at 1.20 atm and 227°C is mixed with 0.200 L of O2 at 501 ton and 127°C in a 400-mL flask at 27°C, what is the pressure in the flask?

Problem 38P A 355-mL container holds 0.146 g of Ne and an unknown amount of Ar at 35°C and a total pressure of 626 mmHg. Calculate the moles of Ar present.

Problem 39P The air in a hot-air balloon at 744 torr is heated from 17°C to 60.0°C. Assuming that the moles of air and the pressure remain constant, what is the density of the air at each temperature? (The average molar mass of air is 28.8 g/mol.)

How many grams of phosphorus react with \(35.5 L\) of \(\mathrm{O}_{2}\) at STP to form tetraphosphorus decaoxide? \(\mathrm{P}_{4}(\mathrm{~s})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{P}_{4} \mathrm{O}_{10}(\mathrm{~s})\) Equation Transcription: O2 Text Transcription: 35.5 L O2 P_4(s) +5O_2(g) rightarrow P_4O_10(s)

Problem 40P A sample of a liquid hydrocarbon known to consist of molecules with five carbon atoms is vaporized in a 0.204-L flask by immersion in a water bath at 101°C. The barometric pressure is 767 torr, and the remaining gas weighs 0.482 g. What is the molecular formula of the hydrocarbon?

Problem 41P A sample of air contains 78.08% nitrogen, 20.94% oxygen, 0.05% carbon dioxide, and 0.93% argon, by volume. How many molecules of each gas are present in 1.00 L of the sample at 25°C and 1.00 atm?

How many grams of potassium chlorate decompose to potassium chloride and \(638 mL\) of \(\mathrm{O}_{2}\) at \(128^{\circ} \mathrm{C}\) and \(752 torr\)? \(2 \mathrm{KCIO}_{3}(s) \rightarrow 2 \mathrm{KCI}(s)+3 \mathrm{O}_{2}(g)\) Equation Transcription: O2 128°C Text Transcription: 638 mL O_2 128°C 752 torr 2KCIO_3(s) rightarrow 2KCI(s)+3O_2(g)

When \(35.6 L\) of ammonia and \(40.5 L\) of oxygen gas at STP burn, nitrogen monoxide and water are produced. After the products return to STP, how many grams of nitrogen monoxide are present? \(\mathrm{NH}_{3}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}(\mathrm{g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})\) [unbalanced] Equation Transcription: Text Transcription: 35.6 L 40.5 L NH_3(g) + O_2(g) rightarrow NO(g)+H_2O(l)

Problem 42P An environmental chemist sampling industrial exhaust gases from a coal-buming plant collects a CO2-SO2-H2O mixture in a 21-L steel tank until the pressure reaches 850. torr at 45°C. (a) How many moles of gas are collected? ________________ (b) If the SO2 concentration in the mixture is 7.95 × 103 parts per million by volume (ppmv), what is its partial pressure? [Hint: ppmv = (volume of component/volume of mixture) × 106.]

How many grams of phosphine (PH3) can form when \(37.5 g\) of phosphorus and \(83.0 L\) of hydrogen gas react at STP? \(P_{4}(s)+H_{2}(g) \rightarrow P H_{3}(g)\) [unbalanced] Equation Transcription: Text Transcription: 37.5 g 83.0 L P_4(s) + H2(g) rightarrow PH_3(g)

Problem 47P Aluminum reacts with excess hydrochloric acid to form aqueous aluminum chloride and 35.8 mL of hydrogen gas over water at 27°C and 751 mmHg. How many grams of aluminum reacted?

Problem 49P “Strike anywhere” matches contain the compound tetraphosphorus trisulfide, which bums to form tetraphosphorus decaoxide and sulfur dioxide gas. How many milliliters of sulfur dioxide, measured at 725 torr and 32°C, can be produced from burning 0.800 g of tetraphosphorus trisulfide?

How many liters of hydrogen gas are collected over water at 18°C and 725 mmHg when 0.84 g of lithium reacts with water? Aqueous lithium hydroxide also forms.

The four sketches below represent piston-cylinder assemblies holding gases. The piston at far left holds a reactant about to undergo a reaction at constant \(T\) and \(P\): Which of the other three depictions best represents the products of the reaction? Equation Transcription: Text Transcription: T P

Problem 51P Xenon hexafluoride was one of the first noble gas compounds synthesized. The solid reacts rapidly with the silicon dioxide in glass or quartz containers to form liquid XeOF4 and gaseous silicon tetrafluoride. What is the pressure in a 1.00-L container at 25°C after 2.00 g of xenon hexafluoride reacts? (Assume that silicon tetrafluoride is the only gas present and that it occupies the entire volume.)

Problem 53P Use the kinetic-molecular theory to explain the change in gas pressure that results from warming a sample of gas.

Problem 54P How does the kinetic-molecular theory explain why 1 mol of krypton and 1 mol of helium have the same volume at STP?

Problem 52P Roasting galena [lead(II) sulfide] is an early step in the industrial isolation of lead. How many liters of sulfur dioxide, measured at STP, are produced by the reaction of 3.75 kg of galena with 228 L of oxygen gas at 220°C and 2.0 atm? Lead(II) oxide also forms.

What is the ratio of effusion rates for \(\mathrm{O}_{2}\) and \(\mathrm{Kr}\)?

Problem 56P What is the ratio of effusion rates for the lightest gas, H2, and the heaviest known gas, UF6?

The graph below shows the distribution of molecular speeds for argon and helium at the same temperature. (a) Does curve \(1\) or \(2\) better represent the behavior of argon? (b) Which curve represents the gas that effuses more slowly? (c) Which curve more closely represents the behavior of fluorine gas? Explain. Equation Transcription: Text Transcription: 1 2

The graph below shows the distribution of molecular speeds for a gas at two different temperatures. (a) Does curve 1 or 2 better represent the behavior of the gas at the lower temperature? (b) Which curve represents the gas when it has a higher \(\overline{E_{k}}\)? (c) Which curve is consistent with a higher diffusion rate? Equation Transcription: Text Transcription: Overline E_k

Helium is the lightest noble gas component of air, and xenon is the heaviest. [For this problem, use \(R = 8.314 J/(molK)\) and in kg/mol.] (a) Calculate the rms speed of helium in winter (\(0^{\circ} \mathrm{C}\)) and in summer (\(30^{\circ} \mathrm{C}\)). (b) Compare urms of helium with that of xenon at \(30^{\circ} \mathrm{C}\). (c) Calculate the average kinetic energy per mole of helium and of xenon at \(30^{\circ} \mathrm{C}\). (d) Calculate \(E_{k}\) per molecule of helium at \(30^{\circ} \mathrm{C}\). Equation Transcription: 0°C 30°C Ek Text Transcription: R = 8.314 J/(molK) 0°C 30°C E_k

Problem 60P At a given pressure and temperature, it takes 4.85 min for a 1.5-L sample of He to effuse through a membrane. How long does it take for 1.5 L of F2 to effuse under the same conditions?

Problem 62P White phosphorus melts and then vaporizes at high temperature. The gas effuses at a rate that is 0.404 times that of neon in the same apparatus under the same conditions. How many atoms are in a molecule of gaseous white phosphorus?

Problem 61P A sample of an unknown gas effuses in 11.1 min. An equal volume of H2 in the same apparatus under the same conditions effuses in 2.42 min. What is the molar mass of the unknown gas?

Problem 64P A mixture of gaseous disulfur difluoride, dinitrogen tetrafluoride, and sulfur tetrafluoride is placed in an effusion apparatus. (a) Rank the gases in order of increasing effusion rate, (b) Find the ratio of effusion rates of disulfur difluoride and dinitrogen tetrafluoride. (c) If gas X is added, and it effuses at 0.935 times the rate of sulfur tetrafluoride, find the molar mass of X.

Problem 65P Do intermolecular attractions cause negative or positive deviations from the PV/RT ratio of an ideal gas? Use Table 5.5 to rank Kr, CO2, and N2 in order of increasing magnitude of these deviations.

Problem 66P Does molecular size cause negative or positive deviations from the PV/RT ratio of an ideal gas? Use Table 5.5 to rank C12 ,H2, and O2 in order of increasing magnitude of these deviations.

Problem 67P Does N2 behave more ideally at 1 atm or at 500 atm? Explain.

Problem 68P Does SF6 (boiling point=16oC at 1 atm) behave more ideally at 150oC or at 20oC?Explain.

Problem 69P Hemoglobin is the protein that transports O2 through the blood from the lungs to the rest of the body. In doing so, each molecule of hemoglobin combines with four molecules of O2. If 1.00 g of hemoglobin combines with 1.53mL of O2 at 37°C and 743 torr, what is the molar mass of hemoglobin?

Chlorine is produced from sodium chloride by the electrochemical chlor-alkali process. During the process, the chlorine is collected in a container that is isolated from the other products to prevent unwanted (and explosive) reactions. If a \(15.50-L\) container holds \(0.5950 kg\) of \(\mathrm{Cl}_{2}\) gas at \(225^{\circ} \mathrm{C}\), calculate (a) \(P_{\text {IGL }}\) (b) \(P_{\text {VDW }}\left(\text { use } R=0.08206 \frac{\mathrm{atm} \cdot \mathrm{L}}{\mathrm{mol} \cdot \mathrm{K}}\right)\) Equation Transcription: Cl2 225°C Text Transcription: 15.50-L 0.5950 kg Cl_2 225°C P_IGL P_VDW (use R=0.08206 atm times L/mol times K)

A baker uses sodium hydrogen carbonate (baking soda) as the leavening agent in a banana-nut quickbread. The baking soda decomposes according to two possible reactions: (1) \(2 \mathrm{NaHCO}_{3}(s) \longrightarrow \mathrm{Na}_{2} \mathrm{CO}_{3}(s)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CO}_{2}(g)\) (2) \(\mathrm{NaHCO}_{3}(s)+\mathrm{H}^{+}(a q) \longrightarrow \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CO}_{2}(g)+\mathrm{Na}^{+}(a q)\) Calculate the volume (in mL) of \(\mathrm{CO}_{2}\) that forms at \(200^{\circ} \mathrm{C}\) and \(0.975 atm\) per gram of \(\mathrm{NaHCO}_{3}\) by each of the reaction processes. Equation Transcription: CO2 200°C NaHCO3 Text Transcription: 2NaHCO_3(s) rightarrow Na_2CO_3(s) + H_2O(l)+CO_2(g) NaHCO_3(s) + H^+(aq) rightarrow H_2O(l)+CO_2(g)+Na^+(aq) CO_2 200°C 0.975 atm NaHCO_3

Three equal volumes of gas mixtures, all at the same \(T\), are depicted below (with gas \(A\) red, gas \(B\) green, and gas \(C\) blue): (a) Which sample, if any, has the highest partial pressure of \(A\) ? (b) Which sample, if any, has the lowest partial pressure of \(B\) ? (c) In which sample, if any, do the gas particles have the highest average kinetic energy? Equation Transcription: Text Transcription: T A B C

Nitrogen dioxide is used industrially to produce nitric acid, but it contributes to acid rain and photochemical smog. What volume of nitrogen dioxide is formed at 735 torr and 28.2°C by reacting \(4.95 \mathrm{~cm}^{3}\) of copper (\(\mathrm{d}=8.95 \mathrm{~g} / \mathrm{cm}^{3}\)) with \(230.0 mL\) of nitric acid (\(\mathrm{d}=1.42 \mathrm{~g} / \mathrm{cm}^{3}, 68.0 \% \ \mathrm{HNO}_{3}\) by mass): \(\mathrm{Cu}(s)+4 \mathrm{HNO}_{3}(a q) \longrightarrow \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{NO}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(l)\) Equation Transcription: 28.2°C 4.95 cm3 d = 8.95 g/cm3 d = 1.42 g/cm3, 68.0% HNO3 Text Transcription: 735 torr 28.2°C 4.95 cm^3 d = 8.95 g/cm^3 230.0 mL d = 1.42 g/cm^3, 68.0% HNO_3 Cu(s) + 4HNO_3(aq) rightarrow Cu(NO_3)_2(aq)+2NO_2(g)+2H_2O(l)

Problem 76P At 1450. mmHg and 286 K, a skin diver exhales a 208-mL bubble of air that is 77% N2,17% O2, and 6.0% CO2 by volume. (a) How many milliliters would the volume of the bubble be if it were exhaled at the surface at 1 atm and 298 K? ________________ (b) How many moles of N2 are in the bubble?

Problem 73P In a certain experiment, magnesium boride (Mg3B2) reacted with acid to form a mixture of four boron hydrides (BxHy), three as liquids (labeled I, II, and III) and one as a gas (IV). (a) When a 0.1000-g sample of each liquid was transferred to an evacuated 750.0-mL container and volatilized at 70.00°C. sample I had a pressure of 0.05951 atm; sample II, 0.07045 atm; and sample III, 0.05767 atm. What is the molar mass of each liquid? ________________ (b) Boron is 85.63% by mass in sample I, 81.10% in II, and 82.98% in III. What is the molecular formula of each sample? ________________ (c) Sample IV was found to be 78.14% boron. Its rate of effusion was compared to that of sulfur dioxide and under identical conditions, 350.0 mL of sample IV effused in 12.00 min and 250.0 mL of sulfur dioxide effused in 13.04 min. What is the molecular formula of sample IV?

Problem 74P When air is inhaled, it enters the alveoli of the lungs, and varying amounts of the component gases exchange with dissolved gases in the blood. The resulting alveolar gas mixture is quite different from the atmospheric mixture. The following table presents selected data on the composition and partial pressure of four gases in the atmosphere and in the alveoli: Atmosphere (sea level) Alveoli Gas Mole% Partial Pressure (torr) Mole% Partial Pressure (torr) N2 78.6 – – 569 O2 20.9 – – 104 CO2 00.04 – – 40 H2O 00.46 – – 47 If the total pressure of each gas mixture is 1.00 atm, calculate: (a) The partial pressure (in torr) of each gas in the atmosphere ________________ (b) The mole % of each gas in the alveoli ________________ (c) The number of O2 molecules in 0.50 L of alveolar air (volume of an average breath of a person at rest) at 37°C

Problem 78P In a collision of sufficient force, automobile air bags respond by electrically triggering the explosive decomposition of sodium azide (NaN3) to its elements. A 50.0-g sample of sodium azide was decomposed, and the nitrogen gas generated was collected over water at 26°C. The total pressure was 745.5 mmHg. How many liters of dry N2 were generated?

Problem 75P Randon (Rn) is the heaviest,and only radioactive, member of Group 8A(18) (noble gases). It is a product of the disintegration of heavier radioactive nuclei found in minute concentrations in many common rocks used for building and construction. In recent years, health concerns about the cancers caused from inhaled residential radon have grown. If 1.0×1015 atoms of radium (Ra) produce an average of 1.373×104 atoms of Rn per second, how many liters of Rn, measured at STP, are produced per day by 1.0 g of Ra?

Problem 79P An anesthetic gas contains 64.81% carbon, 13.60% hydrogen, and 21.59% oxygen, by mass. If 2.00 L of the gas at 25°C and 0.420 atm weighs 2.57 g, what is the molecular formula of the anesthetic?

Problem 80P Aluminum chloride is easily vaporized above 180°C. The gas escapes through a pinhole 0.122 times as fast as helium at the same conditions of temperature and pressure in the same apparatus. What is the molecular formula of aluminum chloride gas?

Problem 81P An atmospheric chemist studying the pollutant SO2 places a mixture of SO2 and O2 in a 2.00-L container at 800. K and 1.90 atm. When the reaction occurs, gaseous SO3 forms, and the pressure falls to 1.65 atm. How many moles of SO3 form?

Problem 82P Liquid nitrogen trichloride is heated in a 2.50-L closed reaction vessel until it decomposes completely to gaseous elements. The resulting mixture exerts a pressure of 754 mmHg at 95°C. (a) What is the partial pressure of each gas in the container? (b) What is the mass of the original sample?

Azodicarbonamide, \(\mathrm{NH}_{2} \mathrm{CONNNCONH}_{2}\), is a blowing (foaming) agent for sponge rubber and expanded plastics. Its decomposition at \(195-202^{\circ} \mathrm{C}\) is given by \(\begin{aligned} \mathrm{NH}_{2} \mathrm{CON}=& \mathrm{NCONH}_{2}(s) \longrightarrow \\ & \mathrm{NH}_{3}(g)+\mathrm{CO}(g)+\mathrm{N}_{2}(g)+\mathrm{HCNO}(g) \\ \mathrm{NH}_{3}(g)+\mathrm{HCNO}(g) & \longrightarrow \text { nonvolatile polymers }(s) \end{aligned} \) Calculate the volume (in mL) of gas, corrected to STP, in the final mixture from decomposition of \(1.00 g\) of azodicarbonamide. Equation Transcription: NH2CONNNCONH2 195–202°C Text Transcription: NH_2CONNNCONH_2 195–202°C NH_2CON=NCONH_2(s) rightarrow NH_3(g)+CO(g)+N_2(g)+HCNO(g) NH_3(g)+HCNO(g) rightarrow nonvolatile polymers(s) 1.00 g

Problem 83P Analysis of a newly discovered gaseous silicon-fluorine compound shows that it contains 33.01 mass % silicon. At 27°C, 2.60 g of the compound exerts a pressure of 1.50 atm in a 0.250-L vessel. What is the molecular formula of the compound?

Problem 85P A gaseous organic compound containing only carbon, hydrogen, and nitrogen is burned in oxygen gas, and the volume of each reactant and product is measured under the same conditions of temperature and pressure. Reaction of four volumes of the compound produces four volumes of CO2. two volumes of N2 and ten volumes of water vapor, (a) What volume of O2 was required? (b) What is the empirical formula of the compound?

Problem 87P By what factor would a scuba diver’s lungs expand if she ascended rapidly to the surface from a depth of 125 ft without inhaling or exhaling? If an expansion factor greater than 1.5 causes lung rupture, how far could she safely ascend from 125 ft without breathing? Assume constant temperature (d of seawater = 1.04 g/mL; d of Hg = 13.5 g/mL).

Containers A, B, and C are attached by closed stopcocks of negligible volume. If each particle shown in the picture represents \(10^{6}\) particles, (a) How many blue particles and black particles are in B after the stopcocks are opened and the pressure stops changing? (b) How many blue particles and black particles are in A after the stopcocks are opened and the pressure stops changing? (c) If the pressure in C, \(P_{c}\), is \(750 torr\) before the stopcocks are opened, what is \(P_{c}\) afterward? (d) What is \(P_{B}\) afterward? Equation Transcription: 106 PC PB Text Transcription: 10^6 P_C 750 torr P_B

Problem 91P Standard conditions are based on relevant environmental conditions. If normal average surface temperature and pressure on Venus are 730. K and 90 atm. respectively, what is the standard molar volume of an ideal gas on Venus?

Problem 89P At a height of 300 km above Earth’s surface, an astronaut finds that the atmospheric pressure is about 10?8 mmHg and the temperature is 500 K. How many molecules of gas are there per milliliter at this altitude?

Problem 93P To study a key fuel-cell reaction, a chemical engineer has 20.0-L tanks of H2 and of O2 and wants to use up both tanks to form 28.0 mol of water at 23.8°C. (a) Use the ideal gas law to find the pressure needed in each tank, (b) Use the van der Waals equation to find the pressure needed in each tank. (c) Compare the results from the two equations.

Problem 94P How many liters of gaseous hydrogen bromide at 29°C and 0.965 atm will a chemist need if she wishes to prepare 3.50 L of 1.20 M hydrobromic acid?

Problem 92P The Hawaiian volcano Kilauea emits an average of 1.5×103 m3 of gas each day, when corrected to 298 K and 1.00 atm. The mixture contains gases that contribute to global warming and acid rain, and some are toxic. An atmospheric chemist analyzes a sample and finds the following mole fractions: 0.4896 CO2, 0.0146 CO, 0.3710 H2O, 0.1185 SO2, 0.0003 S2,0.0047 H2,0.0008 HC1, and 0.0003 H2S. How many metric tons (t) of each gas are emitted per year (1t = 1000 kg)?

The thermal decomposition of ethylene occurs in many industrial contexts, for example, during ethylene transit in pipelines, formation of polyethylene, drying of the gas, and separating it from impurities. The decomposition reaction is \(\mathrm{CH}_{2}=\mathrm{CH}_{2}(g) \longrightarrow \mathrm{CH}_{4}(g)+\mathrm{C} \text { (graphite) }\) Assume that decomposition begins at \(10^{\circ} \mathrm{C}\) and \(50.0 atm\) with a gas density of \(0.215 g/mL\) and the temperature increases by \(950 K\). (a) What is the final pressure of the confined gas (ignore the volume of graphite and use the van der Waals equation)? (b) How does the PV/RT value of \(\mathrm{CH}_{4}\) compare to that in Figure 5.18? Explain. Equation Transcription: 10°C CH4 Text Transcription: CH_2=CH_2(g) rightarrow CH_4(g) + C(graphite) 10°C 50.0 atm 0.215 g/mL 950 K CH_4

Problem 95P A mixture of CO2 and Kr weighs 35.0 g and exerts a pressure of 0.708 atm in its container. Since Kr is expensive, you wish to recover it from the mixture. After the CO2 is completely removed by absorption with NaOH(s), the pressure in the container is 0.250 atm. How many grams of CO2 were originally present? How many grams of Kr can you recover?

Problem 96P Aqueous sulfurous acid (H2SO3) was made by dissolving 0.200 L of sulfur dioxide gas at 19°C and 745 mmHg in water to yield 500.0 mL of solution. The acid solution required 10.0 mL of sodium hydroxide solution to reach the titration end point. What was the molarity of the sodium hydroxide solution?

A person inhales air richer in \(\mathrm{O}_{2}\) and exhales air richer in \(\mathrm{CO}_{2}\) and water vapor. During each hour of sleep, a person exhales a total of about \(300 L\) of this \(\mathrm{CO}_{2}\)-enriched and \(\mathrm{H}_{2} \mathrm{O}\)-enriched air. (a) If the partial pressures of \(\mathrm{CO}_{2}\) and \(\(\mathrm{H}_{2} \mathrm{O}\)\) in exhaled air are each \(30.0 torr\) at 37.0°C, calculate the masses of \(\mathrm{CO}_{2}\) and of \(\(\mathrm{H}_{2} \mathrm{O}\)\) exhaled in 1 h of sleep. (b) How many grams of body mass does the person lose in an 8-h sleep if all the \(\mathrm{CO}_{2}\) and \(\(\mathrm{H}_{2} \mathrm{O}\)\) exhaled come from the metabolism of glucose? \(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(s)+6 \mathrm{O}_{2}(g) \longrightarrow 6 \mathrm{CO}_{2}(g)+6 \mathrm{H}_{2} \mathrm{O}(g)\) Equation Transcription: O2 CO2 H2O 37.0°C Text Transcription: O_2 CO_2 300 L H_2O 30.0 torr 37.0°C C_6H_12O_6(s)+6O_2(g) rightarrow 6CO_2(g)+6H_2O(g)

Problem 105P An equimolar mixture of Ne and Xe is accidentally placed in a container that has a tiny leak. After a short while, a very small proportion of the mixture has escaped. What is the mole fraction of Ne in the effusing gas?

Problem 101P A 6.0-L flask contains a mixture of methane (CH4), argon, and helium at 45°C and 1.75 atm. If the mole fractions of helium and argon are 0.25 and 0.35, respectively, how many molecules of methane are present?

Cylinder Ain the picture below contains \(0.1 mol\) of a gas that behaves ideally. Choose the cylinder (B, C, or D) that correctly represents the volume of the gas after each of the following changes. If none of the cylinders is correct, specify “none.” (a) P is doubled at fixed n and T. (b) T is reduced from \(400 K to 200 K\) at fixed n and P. (c) T is increased from \(100^{\circ} \mathrm{C}\) to \(200^{\circ} \mathrm{C}\) at fixed n and P. (d) \(0.1 mol\) of gas is added at fixed P and T. (e) \(0.1 mol\) of gas is added and P is doubled at fixed T. Equation Transcription: 100°C 200°C Text Transcription: 0.1 mol 400 K to 200 K 100°C 200°C

Problem 100P Combustible vapor-air mixtures are flammable over a limited range of concentrations. The minimum volume % of vapor that gives a combustible mixture is called the lower flammable limit (LFL). Generally, the LFL is about half the stoichiometric mixture, the concentration required for complete combustion of the vapor in air. (a) If oxygen is 20.9 vol % of air, estimate the LFL for n-hexane, C6H14. (b) What volume (in mL) of n-hexane (d =0.660 g/cm3) is required to produce a flammable mixture of hexane in 1.000m3of air at STP?

Problem 103P According to government standards, the 8-h threshold limit value is 5000 ppmv for CO2 and 0.1 ppmv for Br2 (1 ppmv is 1 part by volume in 106 parts by volume). Exposure to either gas for 8 h above these limits is unsafe. At STP, which of the following would be unsafe for 8 h of exposure? (a) Air with a partial pressure of 0.2 torr of Br2 ________________ (b) Air with a partial pressure of 0.2 torr of CO2 ________________ (c) 1000 L of air containing 0.0004 g of Br2: gas ________________ (d) 1000 L of air containing 2.8X 1022molecules of CO2

Problem 106P One way to utilize naturally occurring uranium (0.72% 235U and 99.27% 238U) as a nuclear fuel is to enrich it (increase its 235U content) by allowing gaseous UF6 to effuse through a porous membrane (see the margin note, p. 215). From the relative rates of effusion of ,UF6 and 238UF6, find the number of steps needed to produce uranium that is 3.0 mole % 235U, the enriched fuel used in many nuclear reactors.

Problem 107P In preparation for a combustion demonstration, a professor fills a balloon with equal molar amounts of H2 and O2 but the demonstration has to be postponed until the next day. During the night, both gases leak through pores in the balloon. If 35% of the H2 leaks, what is the O2/H2 ratio in the balloon the next day?

A large portion of metabolic energy arises from the biological combustion of glucose: \(\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6(s)+6\mathrm{O}_2(g)\ \longrightarrow\ 6\mathrm{CO}_2(g)+6\mathrm{H}_2\mathrm{O}(g)\) (a) If this reaction is carried out in an expandable container at \(37^{\circ} \mathrm{C}\) and \(780\). torr, what volume of \(\mathrm{CO}_{2}\) is produced from \(20.0 \ g\) of glucose and excess \(\mathrm{O}_{2}\)? (b) If the reaction is carried out at the same conditions with the stoichiometric amount of \(\mathrm{O}_{2}\), what is the partial pressure of each gas when the reaction is \(50 \%\) complete (\(10.0 \ g\) of glucose remains)? Equation Transcription: Text Transcription: C_6 H_12 O_6(s) + 6O_2(g) rightarrow 6CO_2(g) + 6H_2 O(g) 37 degree C 780 CO_2 20.0 g O_2 O_2 50% 10.0 g

Problem 109P Many water treatment plants use chlorine gas to kill microorganisms before the water is released for residential use. A plant engineer has to maintain the chlorine pressure in a tank below the 85.0-atm rating and, to be safe, decides to fill the tank to 80.0% of this maximum pressure, (a) How many moles of Cl2gas can be kept in the 850.-L tank at 298 K if she uses the ideal gas law in the calculation? (b) What is the tank pressure if she uses the van der Waals equation for this amount of gas? (c) Did the engineer fill the tank to the desired pressure?