Question

The latent heat of fusion of water at 0°C is 335 kJ/kg. How much does the entropy of 1 kg of ice change as it melts into water in each of the following ways:

(a) Heat is supplied reversibly to a mixture of ice and water at 0°C.

(b) A mixture of ice and water at 0°C is stirred by a paddle wheel.

Answer 1

(a)

(ΔS)_system = \(\frac{1\times 335}{273}\) kJ/K

= 1.227 kJ/K

(b) 

(ΔS)_system = \(\int \limits_{273}^{273} m\,c_p\frac{dT}T\) 

= 0