A sample of 2.00 mol argon is confined at low pressure in a volume at a temperature of 50°C. Describe quantitatively the effects of each of the following changes on the pressure, the average energy per atom in the gas, the rootmean - square speed, the rate of collisions with a given area of wall, the frequency of Ar-Ar collisions, and the mean free path:

(a) The temperature is decreased to 250°C.

(b) The volume is doubled.

(c) The amount of argon is increased to 3.00 mol.