A substance has normal boiling point of 400 K If $\mathrm{\Delta }{S}_{\mathrm{vap}}$ at 1 atm and 400 K is 100 JI K mole, then calculate $|\mathrm{\Delta }S{|}_{\text{surrounding }}$ at 1 atm and 200 K for the vaporization process. 

${\mathrm{C}}_{\mathrm{p}}$ of substance in liquid phase= 50 J/mole K 

${\mathrm{C}}_{\mathrm{p}}$ of substance in vapour phase = 40 J/mole K