Most Important Selected Qs for JEE AdvancedChemistryThermodynamics (C)
The normal boiling point of a liquid (A) is 350 ~K . H _ vap at normal boiling point is 35 ~kJ ~mol ⁻¹ . Pick out the correct statement(s). [Assume H _ vap is independent of pressure]
Options
- AS _ vap 100 JK ⁻¹ ~mol ⁻¹ at 350 K and 0.5 ~atm ⁻¹
- BS _ vap 0 JK ⁻¹ ~mol ⁻¹ at 350 K and 0.5 atm
- CS _ vap 100 JK ⁻¹ ~mol ⁻¹ at 350 ~K ^ -2 n d ~ 2.0 ~atm
- DG_ vap 0 ~kJ ~mol ⁻¹ at 350 K and 2.0 atm
Correct answer
D. G_ vap 0 ~kJ ~mol ⁻¹ at 350 K and 2.0 atm
Step-by-step solution
S _ vap at 350 K and 1 atm = 35 1000 350 =100 JK ⁻¹ ~mol ⁻¹ aligned & ( S_ vap )_ 0.5 ~atm = ( S_ vap )_ 1 ~atm +1 R 1 0.5 & 100 JK ⁻¹ ~mol ⁻¹ & ( ~S _ vap )_ 2 ~atm = ( S _ vap )_ 1 ~atm +R 1 2 100 JK ⁻¹ ~mol ⁻¹ & ( G _ vap )_ 2 ~atm = H - T ( S )_ 2 ~atm 0 ~kJ ~mol ⁻¹ aligned