Which of the Following Changes Will NOT Affect the Total

Multiple Choice

Which of the following changes will NOT affect the total pressure of gas in a container, assuming all other factors remain constant?

A) The frequency of collisions of molecules with the walls is increased.
B) The average velocity of the molecules is lowered.
C) The temperature of the sample is altered.
D) Half of the molecules are replaced by an equal number of molecules of a gas with a different molecular weight.
E) The total number of molecules is altered.