Q.

Ice at –5°C is heated to become vapor with temperature of 110°C at atmosphere pressure. The entropy change associated with this process can be obtained from    [2025]

1 ∫268K273KCp,m dT+ΔHm,fusionTf+ΔHm,vaporisationTb+∫273K373KCp,m dT+∫373K383KCp,m dT  
2 ∫268K383KCp dT+ΔHmelting273+ΔHboiling373  
3 ∫268K273KCp,mT dT+ΔHm,fusionTf+ΔHm,vaporisationTb+∫273K373KCp,mdTT +∫373K383KCp,mdTT   
4 ∫268K383KCp dT+qrevT  

Ans.

(3)

Ice(-5°C)→∫268273Cp,mdTT Ice(-0°C)→ΔHm(fusion)Tf Water (-0°C)→∫273373Cp,mdTT Water(100°C)→ΔHm(vap)Tb Water (-0°C)→∫273373Cp,mdTT Water(100°C)