Chapter 05 – Gases
104. Calculate the density of SO2 gas, in grams per liter, at 55C and 1.5 atm.
105. Calculate the molar mass of a gaseous substance if 0.125 g of the gas occupies 93.3 mL
at STP.
Chapter 05 – Gases
106. Select True or False: An aerosol can with a volume of 0.50 L has a bursting point of 2.6
atm. If the can contains 1.0 g CO2 and is heated to 400C, it will burst.
107. Phosgene, a chemical warfare agent used in World War I, consists of 12.41% C, 16.17%
O, and 71.69% Cl. 1.00 L of this gas at STP has a mass of 4.42 g. What is the molecular
formula of phosgene?
Chapter 05 – Gases
108. The van der Waals equation is a modification of the ideal gas equation. What two factors
does this equation account for?
109. On a spring morning (20.C) you fill your tires to a pressure of 2.25 atmospheres. As you
ride along, the tire heats up to 45C from the friction on the road. What is the pressure in your
tires now in units of atmospheres?
Chapter 05 – Gases
110. A gas-filled balloon with a volume of 12.5 L at 0.90 atm and 21C is allowed to rise to
the stratosphere where the temperature is –5C and the pressure is 1.0 millibar. What is the
final volume of the balloon in Liters? 1.000 atm = 1.013 bar.
111.
What volume (L) of H2 is formed at STP when 6.0 g of Al is treated with excess NaOH?
2NaOH + 2Al + 6H2O → 2NaAl(OH)4 + 3H2(g)
Chapter 05 – Gases
112.
A convenient way to produce very high purity oxygen in the laboratory is to decompose KMnO4(s) at high temperature
according to the following chemical equation:
2KMnO4(s) → K2MnO4(s) + MnO2(s) + O2(g)
If 2.50 L of O2(g) is needed at 1.00 atm and 20.C, what mass (in grams) of KMnO4(s) should be decomposed? Assume the
decomposition of KMnO4(s) goes to completion.
113.
The following data describes an initial and final state for an ideal gas. Given that the amount of gas does not change in the
process, what is the final temperature (C) of the gas?
Chapter 05 – Gases
114.
The following data describes an initial and final state for an ideal gas. Given that the amount of gas does not change in the
process, what is the final volume (mL) of the gas?
115.
The following data describes an initial and final state for an ideal gas. Given that the amount of gas does not change in the
process, what is the final pressure (atm) of the gas?
Chapter 05 – Gases
116.
The following data describes an initial and final state for an ideal gas. Given that the amount of gas does not change in the
process, what was the initial volume (L) of the gas?
117. Today is a beautiful day for a picnic in the mountains, so we seal our peanut butter
sandwich in a plastic sandwich bag at the base of the mountain. The approximate volume of
the sandwich bag not occupied by the sandwich is 200. mL. The pressure at the base of the
mountain is 1.0 atm. If the pressure at the top of the mountain is 0.80 atm, what is the final
volume (mL) of gas in our sandwich bag?
Chapter 05 – Gases
118. Which one of the following is not an example of an element that occurs as a gas at room
temperature and pressure?
119. Which of the following is not an example of a compound that exists as a gas at room
temperature and pressure.
Chapter 05 – Gases
120. Select True or False: At constant pressure, the density of a gas increases with an increase
in temperature.
121. At STP, 1 mole of gas has a molar volume of 22.4 L. What is the density (g/L) of oxygen
at STP?
Chapter 05 – Gases
122.
Ammonium nitrite undergoes decomposition to produce only gases as shown below.
NH4NO2(s) → N2(g) + 2H2O(g)
How many liters of gas will be produced by the decomposition of 32.0 g of NH4NO2 at 525C and 1.5 atm?
123.
In an effort to address concerns about global warming, a power plant in Portland, Oregon is designed to take all of its exhaust
gases from its boilers and recycle the CO2 using the Solvay process to make sodium hydrogen carbonate. The reaction is
shown below.
NH3(g) + H2O(l) + CO2(g) + NaCl(aq) → NaHCO3(aq) + NH4Cl(aq)
How many liters each of NH3 and CO2 (both at STP) would be consumed to produce 3.00 kg of sodium bicarbonate?
Chapter 05 – Gases
124.
Baking powder is made up of sodium hydrogen carbonate and calcium hydrogen phosphate. When baking powder is wet,
these components react to produce carbon dioxide. The equation for this reaction is given below.
NaHCO3(aq) + CaHPO4(aq) → NaCaPO4(aq) + CO2(g) + H2O(l)
Assuming all of the carbon dioxide was released as a gas, how many liters of CO2(g) would be formed at room temperature
from 4.00 g of NaHCO3 and excess CaHPO4?
125. Packaged cake mixes usually contain baking powder, a mixture of sodium hydrogen
carbonate and calcium hydrogen phosphate that react to produce carbon dioxide gas when
they are heated in water. The CO2(g) formed allows the cake to “rise.” When such cake mixes
are used at high altitudes, often the cake will rise too much and collapse, unless special
instructions are followed. Why does this happen?
Chapter 05 – Gases
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126. Many automobiles produce about 5 grams of NO for each mile they are driven. How
many liters of NO gas at STP would be produced on a 100-mile trip?
Fill in the Blank Questions
127. A particular coal sample contains 2.32% S. When the coal is burned, the sulfur is
converted to sulfur dioxide gas. What volume (L) of SO2(g), measured at 25C and 749
mmHg, is produced by burning 2.0 106 lb of this coal? (1 lb = 454 g)
Chapter 05 – Gases
128. At standard temperature and pressure, a given sample of water vapor occupies a volume
of 2.80 L. How many moles of water vapor are present?
129. Gasoline (which can be considered to be octane, C8H18) burns in oxygen to produce
carbon dioxide and water. What volume (L) of oxygen at STP is necessary to react with 1.0
gal of gasoline?
(The density of gasoline is 0.81 g/mL. 1 gal = 3.78 L)
Chapter 05 – Gases
130. Gasoline (which can be considered to be octane, C8H18) burns in oxygen to produce
carbon dioxide and water. What volume (L) of carbon dioxide at STP is generated as a result
of the combustion of 1.0 gal of gasoline?
(The density of gasoline is 0.81 g/mL. 1 gal = 3.78 L)