Question

Entropy change involved in conversion of one mole of liquid water at $373K$ to vapour at the same temperature (latent heat of vaporisation of water $=2.257kJ{g}^{-1})$.

• A. $30.7J{K}^{-1}mo{l}^{-1}$
• B. $60.3J{K}^{-1}mo{l}^{-1}$
• C. $9.8J{K}^{-1}mo{l}^{-1}$
• D. $108.9J{K}^{-1}mo{l}^{-1}$

Answer 1

The correct option is D $108.9J{K}^{-1}mo{l}^{-1}$

$△H_{vap}=2.257kJ{g}^{-1}=(2.257\times 18)kJmo{l}^{-1}=40.626kJmo{l}^{-1}△S_{vap}=\frac{40.626}{373}=0.1089kJ{K}^{-1}mo{l}^{-1}$