Question

A mole of a monatomic ideal gas has pressure P , volume V, and temperature T. Which of the following processes would result in the greatest amount of energy added to the gas from heat?

(A) A process doubling the temperature at constant pressure.

(B) An adiabatic free expansion doubling the volume.

(C) A process doubling the pressure at constant volume.

(D) An adiabatic expansion doubling the volume.

(E) A process doubling the volume at constant temperature.

Answer 1

Correct option (A) A process doubling the temperature at constant pressure.

Explanation:

Q = 0 in adiabatic processes (choices B and D). Q = ∆U – W. Choices A and C have the same ∆T and hence, same ∆U and since doubling the volume at constant pressure involves negative work, while doubling the pressure at constant volume does no work, ∆U – W is greater for the constant pressure process. (The constant temperature process has ∆U = 0 and less work than the constant pressure process).