how much heat is absorbed or released by the water when?

Question

50 g(l) H2O at 0*C-> 50g(s) H2O at 0*C?
A) 222 cal released
B) .22 kcal released
C) 4kcal released
D) 4000 cal absorbed

Answer 1

D) 4000 cal released. The latent heat of fusion of water (ice) is 80 cal/g. That's the amount of heat it takes to melt 1 g of ice at 0degC to 1 g of water at 0degC. But it works in reverse also. The same 80cal/g is released when 1g water freezes.