Question

Fixed mass of an ideal gas collected in a 24.64 litre sealed rigid vessel at 10 atm is heated from `-73^(@)C` to `27^(@)C` calculate change in gibbs free energy if entropy of gas is a function of temperature as `S=2+10^(-2)T(J//K)(1l atm=0.1kJ)`
A. `1231.5` J
B. `1281.5` J
C. `781.5` J
D. 0

Answer 1

Correct Answer - C
At constant volume, `(P_(1))/(T_(1))=(P_(2))/(T_(2))`
`rArr" "P_(2)=1xx(300)/(200)=(3)/(2)`
and `V_(1)=24.63L`
for single phase
`because" "dG=Vdp-"S dT"`
`DeltaG=V.DeltaP-int(2+10^(-2)T).dT`
`=1231.5-200-(10^(-2)xx50,000)/(2)`
= 781.5 J