You may want to reference (Pages 412 - 415)Section 10.7 while completing this problem.
Consider two gas cylinders of the same volume and temperature, one containing 1.0 mol of propane, C3H8, and the other 2.0 mol of methane, CH4. Which of the following statements is true?
(a) The C3H8 and CH4 molecules have the same urms
(b) The C3H8 and CH4 molecules have the same average kinetic energy
(c) The rate at which the molecules collide with the cylinder walls is the same for both cylinders