19. What is the mole fraction of H2 in a mixture with a total pressure of 800 torr when the partial pressure of H2 is 90 torr?
a. 0.11
b. 8.8
c. 1.0
d. 0.5
e. 0.88
20. The kinetic theory of gases assumes that collisions __________
a. with the walls of the container cause energy to be lost.
b. of molecules with each other cause energy to be lost.
c. are caused by molecules attracting each other.
d. do not result in a change in the energy of the molecules.
e. do not occur because the size of the molecules is negligible.
21. Which of these gases (Ar, N2O, H2) has the same average kinetic energy at 25°C as CO2?
a. Ar
b. N2O
c. H2
d. They are all the same as CO2.
e. They are all different from CO2.
22. The following graph shows the gas speed distributions for four different gases, all at the same temperature. Which of the curves is for the lightest gas?
a. a
b. b
c. c
d. d