Answer:
ΔS = nR(In (Vf/Vi))
Step-by-step explanation:
We are told the temperature has the same value and therefore it's constant.
Formula for change in entropy isothermally is;
ΔS = nR(In (V2/V1))
V2 is final volume and V1 is initial volume.
We are told that the volume changes from Vi to Vf.
Thus, V2 = Vf and V1 = Vi
Hence;
ΔS = nR(In (Vf/Vi))