Q: Two moles of an ideal gas at 300K were cooled at constant volume so that the pressure is reduced to half the initial value. Then as a result of heating at constant pressure, the gas expands till it attains the original temperature. Find the total heat absorbed by the gas, if R is the gas constant.
(a) 150R J
(b) 300R J
(c) 75R J
(d) 100R J
Ans: (c)