Question

When $1kg$ of ice at $0^{o}C$ melts to water at $0^{o}C$, the resulting change in its entropy, taking the latent heat of ice to be $80cal/C^o$?

• A. $273cal/K$
• B. $8\times {10}^{4}cal/K$
• C. $80calK$
• D. $293cal/K$

Answer 1

The correct option is D $293cal/K$

Here

$L=80cal/k$

$m=1kg=1000g$

$T=273K$

Heat absorbed in change of phase $Q=mL$

$\Delta Q=1000\times 80=8\times {10}^{4}cal$

$S=\frac{\Delta Q}{T}$

$=\frac{8\times {10}^4}{273}$

$=293cal/k$