posted by michael .
Entropy of melting
A block of a certain substance (m = 0.3 kg) sits in a cold room at its melting point 170 K. A lab demonstrator supplies heat at a rate of 200 W for 140 seconds by focusing light on the block to (just) completely melt the block.
(a) What is the latent heat of fusion of the substance?
(b)What is the change in entropy of the block due to the melting process?
(a) Latent H.O.F. = Q
= (energy added during melting)/(mass)
(b) Entropy Change = Q/T
= (Energy added)/(170 K)