Chapter 15, Problem 37P

To determine

To find : The change in entropy.

Answer to Problem 37P

  $29.30\text{kcal}\cdot {\text{K}}^{-1}$

Explanation of Solution

Given:

Volume of water $=1{\text{m}}^{\text{3}}$

Formula Used :

  $V=\frac{m}{\rho },\Delta S=\frac{\Delta Q}{T},\Delta Q=m{L}_f$

Calculation :

  $\begin{array}{c}\Delta Q=m{L}_f\\ =\rho V{L}_f\end{array}$

  $\Rightarrow \Delta Q=100\times 1\times 80\text{kcal}$

  $\Rightarrow \Delta Q=8\times {10}^4\text{kcal}$

Now,

  $\Rightarrow \Delta S=\frac{8\times {10}^4}{273}\text{kcal}$

  $\Rightarrow \Delta S=\frac{8000}{273}=29.30\text{kcal}\cdot {\text{K}}^{-1}$