Match the LIST-I with LIST-II for an isothermal process of an ideal gas system. 
Choose the correct answer from the options given below:
A-IV, B-II, C-III, D-I
To solve this matching question for an isothermal process of an ideal gas, we need to analyze each process described in List-I and match it with the corresponding formula for work done from List-II.
In a reversible isothermal expansion, the work done is given by the formula: \(w = -nRT \ln\left(\frac{V_f}{V_i}\right)\) This matches with option II.
During a free expansion, the system does no work since there is no external pressure against which the system expands. Hence, the work done, \(w = 0\). This corresponds to option I.
For an irreversible expansion against a constant external pressure, the work done is given by: \(w = -P_{ex}(V_f - V_i)\) This matches with option III.
Similarly, for irreversible compression against a constant external pressure, the work done is: \(w = -P_{ex}(V_i - V_f)\) This corresponds to option IV.
Based on the analysis above, the correct matching of List-I with List-II is:
Therefore, the correct answer is: A-II, B-I, C-III, D-IV.