Download Chapter 5 Worksheet

CHEM 31 SI 10/18/09
Chapter 5 Worksheet
Chapter 5 Worksheet
1. Suppose you have one mole of an ideal gas.
A) What is the effect on the volume if the pressure is tripled (T remains constant)
B) What is the effect on the volume if the temperature is increased by a factor of 2.5
(Pressure remains constant)?
C) You add 2 more moles of the gas
2. Suppose on another universe, 220.05 grams of dry ice (solid CO2) is allowed to sublime to a
gaseous phase at 0o C. 224.15 liters of gas are collected at 1atm.
Calculate the R-value on this universe and indicate the units of R.
What is the Molar Volume at STP in this universe?
3. What is the density of Xenon gas at STP?
4. Why is moist air less dense than dry air?
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CHEM 31 SI 10/18/09
Chapter 5 Worksheet
5. (from an old Bill Cleaver Exam) Ammonium nitrate, a common fertilizer, is used as an
explosive in fireworks and bombs. How many liters of gas at 307o C and 1.00atm are formed by
the explosive decomposition of 15.0kg of ammonium nitrate?
2 NH4NO3 (s) → 2 N2 (g) + O2 (g) + 4 H2O (g)
6. You are inflating a balloon at 1atm. You add 1 liter of 30o C air with each breath. After 5
breaths, how many grams of nitrogen (N2) gas are contained in the balloon, assuming your
expired air is 78% nitrogen by volume.
7. What is the molar mass of a compound if 2.00 liters of the gas weighs 2.57 grams at 25o C and
.420 atm.
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CHEM 31 SI 10/18/09
Chapter 5 Worksheet
8. (#67 From the textbook) The H2 gas formed in a chemical reaction is collected over water at
30.0o C at a total pressure of 732 mmHg. What is the partial pressure of hydrogen gas collected
in this way? What is the mole ratio? If the total volume of gas collected is 722mL, what mass of
H2 gas is collected? (Vapor pressure at 30.0o C = 31.86 mm Hg)
9. (#77 from the textbook) Consider the following reaction:
CH4 (g) + H2O (g) → CO (g) + 3H2 (g)
25.5 liters of methane gas at 732 torr and 125o C react with 22.8 liters of water vapor at 702 torr
and 125o C. The reaction produces 26.2 liters of hydrogen gas measured at STP. What is the
percent yield of the reaction?
10. How does the kinetic molecular theory explain why 1 mol of krypton gas and 1mol of helium
gas have the same volume and pressure at STP?
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CHEM 31 SI 10/18/09
Chapter 5 Worksheet
11. (similar to #87 and #88 in the text) Draw an axis in which molecular velocity = x-axis and
number of molecules = y-axis. (A) Draw two curves that approximate the distribution of
velocities for the same molecule at two different temperatures. (B)Draw two curves that
approximate the distribution of velocities for two molecules of different molar mass.
12. Identify the two key assumptions that the ideal gas law is based on. Under what conditions
might they be invalid? In what direction must Pressure and Volume be adjusted (up or down) to
formulate a gas law that is valid under all conditions?
13. (#91 from the text) Use the van der Waals equation and the ideal gas equation to calculate
the volume of 1.000 mol of neon gas at a pressure of 500.0 atm and a temperature of 355.0 K.
Explain why the two values are different. (For Ne: a = 0.211 L2 atm/mol2 and b = 0.0171 L/mol)
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