Chemistry · PYQ NEET UG 2016(2)

For a sample of perfect gas when its pressure is changed isothermally from \( P_i \) to \( P_f \) the entropy change is given by

1. \( \Delta S = RT \ln(\frac{P_i}{P_f}) \)
2. \( \Delta S = nR \ln(\frac{P_i}{P_f}) \)
3. \( \Delta S = nR \ln(\frac{P_f}{P_i}) \)
4. \( \Delta S = nRT \ln(\frac{P_f}{P_i}) \)