In an isochoric process where the gas's internal energy decreases by 50 J, no work is done by the gas because the volume is constant. The work done is 0 J.
Explanation:In an isochoric process (also known as an isovolumetric process), the volume of a gas remains constant. According to the first law of thermodynamics, the change in internal energy (ΔU) of a system is equal to the heat added to the system (Q) minus the work done by the system (W): ΔU = Q - W. In an isochoric process, because the volume does not change, no work is done by the gas (W = 0). Therefore, if the internal energy of the gas decreases by 50 Joules, and no work is done, the amount of heat removed from the gas would be equivalent to the decrease in internal energy, which is -50 Joules.
The answer to the student's question is that in an isochoric process where the internal energy decreases by 50 Joules, no work is done by the gas since the volume is constant; the work done is 0 Joules.