Question

5 mole of an ideal gas expands reversibly from a volume of $8d$ to $80d$ at a temperature of $27$. The change in entropy is:-
(A) $41.57{JK}^{-1}$
(B) $-95.73{JK}^{-1}$
(C) $95.73{JK}^{-1}$
(D) $-41.57{JK}^{-1}$

Answer 1

The correct option is C

We have,

$n=5,v_1=8d{m}^3,v_2=80d{m}^3,T=300k$Constant

Thus the change in entropy is:

$\Delta s=nR$ in $\frac{v_2}{v_1}$

$=5\times 8.314\times \frac{80}{8}$

$=95.73j{k}^{-1}$