1. An isothermal process is one in which T
i
= T
f
which implies ln(T
/T
) = 0. Therefore, with V
/V
= 2,
Eq. 21-4 leads to
∆S = nR ln
V
= (2.50 mol)
8.31
J
mol
·K
ln(2) = 14.4 J/K .