For a sample of perfect gas when its pressure is changed isothermally from P_(i) to P_(f) the entropy change is given by

For a sample of perfect gas when its pressure is changed isothermally

1.	For a sample of perfect gas when its pressure is changed isothermally from P_(i) to P_(f) the entropy change is given by
Answer» `DELTA S = NRT "In" ((P_f)/( P_i))` `Delta S = RT "In" ((P_i)/( P_f))` `Delta S = nR "In" ((P_f)/( P_i))` `Delta S= nR "In" ((P_i)/( P_f))` Solution :`Delta S = NC "In" (T_i)/( T_f) + nR "In" (P_i)/( P_f)` For isothermal `T_i = T_f, "In" 1=0` `therefore Delta S = nR "In" (P_i)/( P_f)`