Calculate entropy change
`H_(2)O(1,1"atm",100^(@)C)toH_(2)O(g,1"atm",110^(@)C)`
`H_(2)O(1,1"atm",100^(@)C)toH_(2)O(g,2"atm",100^(@)C)`
`DeltaH_("vap")=40kJ//mol" "C_(p)(1)=75J//mol//K`
`C_(p)(g)=35J//mol//K`

Explanation

For 1 mol
(i) `underset((A))(H_(2)O(/,1"atm",100^(@)C))tounderset((B))(H_(2)O(g,1"atm",100^(@)C))tounderset((C))(H_(2)O(g,1"atm",110^(@)C))`
`DeltaS_(AtoB)=(DeltaH_("vap"))/T=(40xx1000)/373`
`DeltaS_(StoC)=nC_(p)(g)//nT_(2)/T_(1)=1xx35//n383/373`
(ii) `underset((A))(H_(2)O(/,1"atm",100^(@)C))tounderset((B))(H_(2)O(g,1"atm",100^(@)C))tounderset((C))(H_(2)O(g,2"atm",100^(@)C))`
`DeltaS_(AtoB)=(DeltaH_("vap"))/T=(40.000)/373`
`DeltaS_(StoC)=nR//nP_(2)/P_(1)=1xxR//n1/2`