AP CHEMISTRY WKST
GAS LAWS
NAME: ____________________________
PER: ____
DIRECTIONS: Do the following problems on another sheet of paper. Show your work.
1.
A sample of chlorine gas is placed in a 2.56 L flask at a temperature of 27.5C with a pressure of 48.5 mmHg. If
the chlorine is moved to a new flask with a volume of 345 ml, and if the temperature has changed to 22.6C,
what is the pressure of the gas in the smaller flask?
2.
A balloon filled with N2, O2, CO2 and Ar has the partial pressures of 0.652 atm, 0.222 atm, 0.015 atm and
0.00239 atm respectively for the gases. What is the total pressure in the balloon in torr?
3.
You want to find the volume of some type of new container. You find that a sample of gas put into a 265 ml flask
has a pressure of 136.5 torr at 27.5C. When this gas has been transferred to the new container, the pressure
changed to 96.7 torr at 24.0C. What is the volume of the new container?
4.
A 500.0 mL sample of a gas was collected over water at 21.0°C and 782.2 torr. What will the volume of the “dry”
gas be at STP?
5.
A sample of H2 was collected over water at 27C and occupies 615 ml at 575 mmHg. When the gas is cooled,
the volume decreased to 455 ml and its pressure is reduced to 385 mmHg. What is the temperature of the “dry”
H2 after cooling?
6.
Determine the pressure of 3.250 g O2 in a 1.250 L container at −35.23°C.
7.
What mass of carbon dioxide gas is required to fill a 1.5 L balloon at STP?
8.
Calculate the volume of O2, at STP, required for the complete combustion of 125 g octane (C8H18) to CO2 and
H2O. (need chemical equation)
9.
Calculate the density of ammonia gas at 27°C and 635 torr.
10. A 3.00 L cylinder of He has a pressure of 5.00 atm and a temperature of 27.2°C. If enough He is released to fill a
5.50 L balloon with a pressure of 755 torr, what is the temperature of the He in the balloon?
11. A “vacuum line” is not a complete vacuum but contains some gas under very low pressure. A device called a
McLeod gauge measures the pressure in a vacuum line by compressing a large volume of gas from the system
until it has a much smaller volume but it has a pressure high enough to measure. If a 640.0 ml sample from a
line of unknown pressure were compressed to a volume of 0.048 ml with a pressure of 90.0 kPa, what was the
original pressure in the line? (Assume T doesn’t change.)
12. What is the partial pressure of H2, Ar, and O2 in a 5.0 L tank with a total pressure of 1.105 atm if there is 1.00 g
H2, 20.0 g Ar and 15.7 g O2 in the mixture?
13. A cyclopropane-oxygen mixture (C3H6 + O2) can be used as an anesthetic. Assume that a tank containing such
a mixture has the partial pressure of 170.0 torr for C3H6 and 570.0 torr for O2:
a) What is the mole ratio between the cyclopropane and oxygen in the tank?
b) If the tank contains 160.0 g O2, how many grams of C3H6 are also present?
14. An unknown gas has a density of 0.985 g/L at 738.2 torr and 33.0°C. Determine its molar mass.
15. For the reaction: CaCO3(s) + 2HCl → CaCl2 + CO2(g) + H2O(l)
What volume of concentrated HCl (look up on back of info sheet) is needed to produce 10.00 L of CO2 at 99.25
kPa and -15.29°C?
16. For the reaction: CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
If 3.26 L CH4 reacted at 125°C and 1.356 atm, what volume of O2 will also react at the same temperature and
pressure?
17. A 0.345 g sample of an unknown gas was collected in a 100.0 mL container. If the pressure of the gas is 110.34
kPa and the temperature of it is 25.50°C, what is the molar mass of the gas?
-218. A gas consisting on only carbon and hydrogen has an empirical formula of CH 2. The gas has a density of
1.65 g/L at 27°C and 734 torr. Determine the molar mass and molecular formula of the gas.
19. Calculate the average kinetic energy of N2 gas at 492 K.
20. Calculate the root mean square velocity of CO2 gas at 150.0°C.
21. How much faster is the rate of effusion for O2 than SO3?
22. O2 has a rate of effusion of 39.25 mL/min at some temperature. If an unknown gas has a rate of effusion of
41.39 mL/min, what is the molar mass of the unknown gas?
23. For the reaction: 2KMnO4(s) + 5H2C2O4(aq) + 3H2SO4(aq) → 10CO2(g) + K2SO4(aq) + 2MnSO4(aq) + 8H2O(l)
If the following amounts of reactants were placed into a container, what volume of CO 2 will form at STP?
25.00 g KMnO4
250.0 mL of 1.25 M H2C2O4
10.0 mL of 17.8 M H2SO4