Chemical Thermodynamics Question 354
Question: Fixed mass of an ideal gas contained in a 24.63 L sealed rigid vessel at 1 atm is heated from - $ 73{}^\circ C $ to $ 27{}^\circ C $ . Calculate change in gibb’s energy if entropy of gas is a function of temperature as $ S=2+{{10}^{-2}}T( J/K ): $ (Use 1 atm $ L=0.1kJ $ )
Options:
A) 1231.5 J
B) 1281.5 J
C) 781.5J
D) 0
Show Answer
Answer:
Correct Answer: C
Solution:
- At constant volume, $ \frac{P_1}{T_1}=\frac{P_2}{T_2} $
$ \Rightarrow P_2=1\times \frac{300}{200}=\frac{3}{2} $ and $ V_1=24.63L $ for single phase
$ \therefore dG=Vdp-SdT $
$ \Delta G=V\Delta P\int{( 2+{{10}^{-2}}T )}dt $
$ =1231.5-200-( \frac{{{10}^{-2}}\times 50,000}{2} ) $
$ =781.5J $
