Question

Calculate the entropy change for the conversion of following :

(a) 1 g ice to water at 273 K, ΔH_f for ice = 6.025 kJ mol^-1.

(b) 36 g water to vapour at 373 K; ΔH_v for H₂O = 40.63 kJ mol^-1.

Answer 1

(a)

Now 18 g ice melts showing a change in entropy = 22.1

1 g ice melts showing a change in entropy = 22.1/18 x1

= 1.227 JK^-1

^{18 g H₂O vaporises to show a change in entropy = 108.9}

^{36 g H₂O vaporises to show a change in entropy = 108.9 x36/18}

=217.85 Jk^-1