MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

According to the first law of thermodynamics, U = q + w. For an isothermal process, the temperature remains constant ( T = 0). Since the internal energy of an ideal gas depends only on temperature, U = 0 for both isothermal expansion and compression. For an adiabatic process, there is no heat exchange with the surroundings, so q = 0. The first law becomes U = w. During adiabatic expansion, work is done by the gas on the surroundings, meaning w During adiabatic compression, work is done on the gas, meaning w > 0, leading to an increase in internal energy. Answer: Adiabatic expansion of an ideal gas.