• # question_answer One mole of a perfect gas expands isothermally to ten times its original volume. The change in entropy is A)  $0.1\,R$                    B)  $2.303\text{ }R$C)  $10.0\text{ }R$                      D)  100.0 R

${{q}_{rev}}=-{{W}_{rev}}=2.303\,nRT\,\log \frac{{{V}_{2}}}{{{V}_{1}}}$ $\Delta S=\frac{{{q}_{rev}}}{T}=2.303\,\,n\,R\,\log \frac{{{V}_{2}}}{{{V}_{1}}}$ $n=1$ $\frac{{{V}_{2}}}{{{V}_{1}}}=10$ $\Delta S=2.303\times 1\times R\times \log \,10$ $=2.303\times R\times 1$ $=2.303\,R$