If the latent heat of ice is 80 cal/gm, the increase in entropy when 1 gm of ice at \(0^\circ\mathrm{C}\) is converted into water at \(0^\circ\mathrm{C}\) is

Question and options

If the latent heat of ice is 80 cal/gm, the increase in entropy when 1 gm of ice at

0^\circ\mathrm{C}

is converted into water at

0^\circ\mathrm{C}

Correct answer: A - 0.29 cal/K

\Delta S = Q/T = 80\ \mathrm{cal}/273\ \mathrm{K} \approx 0.29\ \mathrm{cal/K}

for 1 gm of ice. Melting at constant temperature still absorbs heat, so the entropy change is positive, not zero.