Ch.10 - Gases: Their Properties & Behavior
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- At what temperature (°C) will xenon atoms have the same average speed that Br2 molecules have at 20° C?
Problem 96
- At what temperature does the average speed of an oxygen molecule equal that of an airplane moving at 580 mph?
Problem 97
- Which has a higher average speed, H2 at 150 K or He at 375 °C?
Problem 98
- Which has a higher average speed, a Ferrari at 145 mph or a gaseous UF6 molecule at 145 °C?
Problem 99
- A big-league fastball travels at about 45 m/s. At what temperature (°C) do helium atoms have this same average speed?
Problem 100
- Traffic on the German autobahns reaches speeds of up to 230 km/h. At what temperature (°C) do oxygen molecules have this same average speed?
Problem 101
- What is the difference between effusion and diffusion?
Problem 102
- Why does a helium-filled balloon lose pressure faster than an air-filled balloon?
Problem 103
- What is the molecular weight of a gas that diffuses through a porous membrane 1.86 times faster than Xe? What might the gas be?
Problem 104
- Chlorine occurs as a mixture of two isotopes, 35Cl and 37Cl. What is the ratio of the diffusion rates of the three species 135Cl22, 35Cl37Cl, and 137Cl22?
Problem 105
- Rank the following gases in order of their speed of diffusion through a membrane, and calculate the ratio of their diffusion rates: HCl, F2, Ar.
Problem 106
- Which will diffuse through a membrane more rapidly, CO or N2? Assume that the samples contain only the most abundant isotopes of each element, 12C, 16O, and 14N.
Problem 107
Problem 108a
Two 112-L tanks are filled with gas at 330 K. One contains 5.00 mol of Kr, and the other contains 5.00 mol of O2. Considering the assumptions of kinetic–molecular theory, rank the gases from low to high for each of the following properties. (a) Collision frequency
Problem 108b
Two 112-L tanks are filled with gas at 330 K. One contains 5.00 mol of Kr, and the other contains 5.00 mol of O2. Considering the assumptions of kinetic–molecular theory, rank the gases from low to high for each of the following properties. (b) Density (g/L)
Problem 108d
Two 112-L tanks are filled with gas at 330 K. One contains 5.00 mol of Kr, and the other contains 5.00 mol of O2. Considering the assumptions of kinetic–molecular theory, rank the gases from low to high for each of the following properties. (d) Pressure
- The reaction NO1g2 + NO21g2 ∆ N2O31g2 takes place in the atmosphere with Kc = 13 at 298 K. A gas mixture is prepared with 2.0 mol NO and 3.0 mol NO2 and an initial total pressure of 1.65 atm. (b) What is the volume of the container?
Problem 109
- (a) The attractive forces between particles most affect the overall volume of the gas sample at _____ (high or low) pressure. (b) The attractive forces between particles cause the true volume of the gas sample to be ______ (larger or smaller) than the volume calculated by the ideal gas law.
Problem 111
- Assume that you have 0.500 mol of N2 in a volume of 0.600 L at 300 K. Calculate the pressure in atmospheres using both the ideal gas law and the van der Waals equation. For N2, a = 1.351 L^2 atm/mol^2 and b = 0.0387 L/mol.
Problem 112
- Assume that you have 15.00 mol of N2 in a volume of 0.600 L at 300 K. Calculate the pressure in atmospheres using both the ideal gas law and the van der Waals equation. For N2, a = 1.351 L^2 atm/mol^2 and b = 0.0387 L/mol.
Problem 113
- Uranium hexafluoride, a molecular solid used for purification of the uranium isotope needed to fuel nuclear power plants, sublimes at 56.5 °C. Assume that you have a 22.9 L vessel that contains 512.9 g of UF6 at 70.0 °C. (a) What is the pressure in the vessel calculated using the ideal gas law? (b) What is the pressure in the vessel calculated using the van der Waals equation? For UF6, a = 15.80 L² atm/mol²; b = 0.1128 L/mol.
Problem 114
- Use both the ideal gas law and the van der Waals equation to calculate the pressure in atmospheres of 45.0 g of NH3 gas in a 1.000-L container at 0 °C, 50 °C, and 100 °C. For NH3, a = 4.17 L² atm/mol² and b = 0.0371 L/mol.
Problem 115
- Name the regions of the atmosphere. What property is used to distinguish between different regions of the atmosphere?
Problem 116
- The Earth's atmosphere has a mass of approximately 5.15 * 1015 kg. If the average molar mass of air is 28.8 g/mol, how many moles of gas make up the atmosphere? What is the volume of the atmosphere in liters under conditions of STP? (Note: The average molar mass of air is the weighted average of the molar mass of nitrogen and oxygen. 0.20132.0 g>mol2 + 0.80128.0 g>mol2 = 28.8 g>mol.)
Problem 117
- The troposphere contains about three quarters of the mass of the entire atmosphere. The troposphere is only 12 km thick while the whole atmosphere is about 120 km thick. Explain why the troposphere contains such a large fraction of the total mass.
Problem 118
- The percent by volume of oxygen (20.95%) is constant throughout the troposphere. (a) Express this percentage as a mole fraction.
Problem 119
- How many times larger is carbon dioxide’s contribution to the greenhouse effect compared to methane? (Use radiative forcing values in Table 10.7 to compare the two gases.)
Problem 127
- N2O has a GWP value of 310 and CO2 has a GWP value of 1, but CO2 makes a greater contribution to the greenhouse effect. Explain.
Problem 128
- What are the trends in atmospheric CO2 and CH4 concentrations over the past 150 years and over several hundred thousand years?
Problem 131
- A driver with a nearly empty fuel tank may say she is 'running on fumes.' If a 15.0-gallon automobile gas tank had only gasoline vapor remaining in it, what is the farthest the vehicle could travel if it gets 20.0 miles per gallon on liquid gasoline? Assume the average molar mass of molecules in gasoline is 105 g/mol, the density of liquid gasoline is 0.75 g/mL, the pressure is 743 mm Hg, and the temperature is 25 °C.
Problem 134
Problem 135a,b
Pakistan's K2 is the world's second-tallest mountain, with an altitude of 28,251 ft. Its base camp, where climbers stop to acclimate, is located about 16,400 ft above sea level. (a) Approximate atmospheric pressure P at different altitudes is given by the equation P = e-h/7000, where P is in atmospheres and h is the altitude in meters. What is the approximate atmospheric pressure in mm Hg at K2 base camp? (b) What is the atmospheric pressure in mm Hg at the summit of K2?