Name________________________
Period________________________
Kinetic Theory, Molar Mass, Rates of Diffusion and Gas Stoichiometry Problems
1. Consider three identical flasks filled with different gases.
a) Flask A : CO at 1 atm and 0 deg C
b) Flask B: N2 at 0.33 atm and 0 deg C
c) Flask C: H2 at 0.13 atm and 0 deg C
a) In which flask(s) will the molecules have the greatest average kinetic energy?
b) In which flask(s) will the molecules have the greatest average velocity?
2. You have a 1 liter container of neon gas at STP. Will the average kinetic energy, the average
velocity, and frequency of collisions of gas molecules with the walls of the container (pressure)
increase (+), decrease (-) or remain the same (=) under each of the conditions?
Frequency of
collisions of
Average kinetic
Average
molecules with
Condition:
energy
velocity
container
The temperature is increased to
100 deg C
The temperature is decreased to –
50 deg C
The volume is decreased to 0.5
liters
The number of moles of Ne is
doubled
3. Compare the rates of diffusion of H2 and N2 gases. (calculate the ratio of their velocities using
Graham’s law – the gas that moves the fastest, diffuses the fastest)
4. A sample of H2 diffuses 8.94 x faster than an unknown gas. What is the molar mass of the
unknown gas?
5. At a certain temperature and pressure, Cl 2 molecules have a velocity of 0.038 m/s. What is
the velocity of SO2 molecules under the same conditions?
Name________________________
Period________________________
6. The diffusion rate of a gas is measured and determined to be 31.50 ml/min. Under identical
experimental conditions, the diffusion rate of O2 is found to be 30.5 ml/min. If the choices are
CH4, NO, CO, CO2, NO2, what is the identity of the unknown gas?
7. You have two balloons filled with air. The smaller balloon holds 500 ml and the larger balloon
holes 1500 ml. Use the kinetic theory to explain each of the following situations.
a) if both balloons are at room temperature (20 deg C) and atmospheric pressure, in which
balloon (if either) are the molecules moving faster? Explain
b) The 500 ml balloon is placed in an oven at 37 deg C. What happens to the speed of the
molecules? Explain
c) What would you expect to happen to the volume of the balloon in this situation? Why?
8. Explain why a helium balloon deflates faster than a balloon filled with air (the main
components of are are N2, O2, CO2)
9. The rate of diffusion of a particular gas was measured and found to be 24 ml/min. Under the
same conditions, the rate of effusion of pure methane (CH 4) gas is 47.8 ml/min. What is the
molar mass of the unknown gas?
10. What is the molar mass of a gas that diffused 0.906 times as fast as argon gas?