Question

Assuming `DeltaH^(@) and S^(@)` do not change with temperature. Calculate, the boiling point of liquid A uing the thermodynamic data given below:
`{:(undersetunderset(S^(@)(JK^(-1)mol^(-1)))(DeltaH^(@)(kJ//mol))("Thermodynamic data"),|,undersetunderset(100)(-130)(A(l)),|,underset underset(200)(-100)A(g)):}`
A. 300K
B. 130 K
C. 150 K
D. 50 K

Answer 1

Correct Answer - A
`A(l)hArrA(g)`
`DeltaH=DDeltaH_(A(g))^(@)-DetlaH_(A(l))^(@)`
`=-100-(-130)=30kJ`
`DeltaS=S_(A(g))^(@)-S_(A(l))^(@)`
`=200-100=100JK^(-1)" "mol^(-1)`
At equilibrium `DeltaG=DeltaH-TDeltaS=0`
`thereforeT=(DeltaH)/(DeltaS)=(30xx1000)/(100)=300K`