Chapter 11 Homework


11.1 Volume-Mass Relationships of Gases

1. At STP, what is the volume of 7.08 mol of nitrogen gas? soln
2. A sample of hydrogen gas occupies 14.1 L at STP. How many moles of the gas are present? soln
3. At STP, a sample of neon gas occupies 550. cm3. How many moles of neon gas does this represent? soln
4. What is the mass of 1.33 x 104 mL of oxygen gas at STP? soln
5. What is the volume of 77.0 g of nitrogen dioxide gas, NO2, at STP? soln
6. At STP, 3 L of chlorine is produced during a chemical reaction. What is the mass of this gas. soln
7. Define molar volume.
8. How many moles of oxygen gas are there is 135 L of oxygen at STP? soln

11.2 The Ideal Gas Law - The Ideal Gas Constant - Finding P, V, T, or n from the Ideal Gas Law

1. What pressure, in atmospheres, is exerted by 0.325 mol of hydrogen gas in 4.08 L container at 350 C? soln
2. A gas sample occupies 8.77 L at 200 C. What is the pressure, in atmospheres, given that there are 1.45 mol of gas in the sample? soln
3. A sample that contains 4.38 mol of a gas at 250 K has a pressure of 0.857 atm. What is the volume? soln
4. How many liters are occupied by 0.909 mol of nitrogen at 1250C and 0.901 atm pressure? soln
5. How many grams of carbon dioxide gas are three in a 45.1 L container at 340 C and 1.04 atm? soln
6. What is the mass, in grams, of oxygen gas in a 12.5 L container at 450 C and 7.22 atm? soln
7. A sample of carbon dioxide with a mass of 0.30 g was placed in a 250 mL container at 400. K. What is the pressure exerted by the gas? soln

11.3 The Ideal Gas Law - The Ideal Gas Constant - Finding Molar Mass or Density from the Ideal Gas Law

1. What is the molar mass of a gas if 0.427 g of the gas occupies a volume of 125 mL at 20.00 C and 0.980 atm? soln
2. What is the density of a sample of ammonia gas, NH3, if the pressure is 0.928 atm and the temperature is 63.00 C? soln
3. The density of a gas was found to be 2.0 g/L at 1.50 atm and 270 C. What is the molar mass of the gas? soln
4. What is the density of argon gas, Ar, at a pressure of 551 torr and a temperature of 250 C? soln
5. What is the volume in liters, of 0.100 g of C2H2F4 vapor at 0.0928 atm and 22.30 C? soln
6. Name two quantities besides pressure, mass, volume, and number of moles that can be calculated using the ideal gas law.

11.4 Stoichiometry of Gases - Volume-Volume Calculations

1. Assuming all volume measurements are made at the same temperature and pressure, what volume of hydrogen gas is needed to react completely with 4.55 L of oxygen gas to produce water vapor according to the following balanced equation:

2 H2 + O2 ---> 2 H2O

soln

2. What volume of oxygen gas is needed to react completely with 0.626 L of carbon monoxide gas, CO, to form gaseous carbon dioxide according to the following balanced equation:

2 CO + O2 ---> 2 CO2 Assume all volume measurements are made at the same temperature and pressure. soln

11.5 Stoichiometry of Gases - Volume-Mass & Mass-Volume Calculations

1. What mass of sulfur must be used to produce 12.61 L of gaseous sulfur dioxide at STP according to the following balanced equation:

S8 + 8 O2 ---> 8 SO2

soln

2. How many grams of water can be produced from the complete reaction of 3.44 L of oxygen gas, at STP, with hydrogen gas according to the following balanced equation:


2 H2 + O2 ---> 2 H2O

soln
3. What volume of chlorine gas at 380 C and 1.63 atm is needed to react completely with 10.4 g of sodium to form NaCl according to the following balanced equation:

2 Na + Cl2 ---> 2 NaCl

soln

4. How many liters of gaseous carbon monoxide at 270 C and 0.247 atm can be produced from the burning of 65.5 g of carbon according to the following equation?

2 C + O2 ---> 2 CO

soln

11.6 Effusion and Diffusion

1. A sample of hydrogen effuses through a porous container about 9 times faster than an unknown gas. Estimate the molar mass of the unknown gas. soln
2. Compare the rate of effusion of carbon dioxide with that of hydrogen chloride at the same temperature and pressure. soln
3. If a molecule of neon gas travels at an average of 400 m/s at a given temperature, estimate the average speed of a molecule of butane gas, C4H10, at the same temperature. soln
4. Compare diffusion with effusion.
5. List the following gases in order of increasing average molecular velocity at 250 C:
a) H2O;
b) He
c) HCl
d) BrF
e) NO2