Question
For the process $${H_2}O\left( l \right)\, \to \,{H_2}O\left( g \right)$$ at $$T = {100^ \circ }C$$ and 1 atmosphere pressure, the correct choice is
A.
$$\Delta {S_{{\text{system}}}} > \,0\,{\text{and}}\,\Delta {S_{{\text{surroundings}}}} > 0$$
B.
$$\Delta {S_{{\text{system}}}} > \,0\,{\text{and}}\,\Delta {S_{{\text{surroundings}}}} < 0$$
C.
$$\Delta {S_{{\text{system}}}} < \,0\,{\text{and}}\,\Delta {S_{{\text{surroundings}}}} > 0$$
D.
$$\Delta {S_{{\text{system}}}} < \,0\,{\text{and}}\,\Delta {S_{{\text{surroundings}}}} < 0$$
Answer :
$$\Delta {S_{{\text{system}}}} > \,0\,{\text{and}}\,\Delta {S_{{\text{surroundings}}}} < 0$$
Solution :
Given conditions are boiling conditions for water due to which
$$\eqalign{
& \Delta {S_{total}} = 0 \cr
& \Delta {S_{system}} + \Delta {S_{surroundings}} = 0 \cr
& \Delta {S_{system}} = - \Delta {S_{surroundings}} \cr
& {\text{For}}\,{\text{process,}}\,\,\Delta {S_{system}} > 0 \cr
& \Delta {S_{surroundings}} < 0 \cr} $$