Q. The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of 10 dm3 at 27°C is to a volume of 100 dm3
A) 38.3 J/ mole / K
B) 42.3 J/ mole / K
C) 32.3 J/ mole / K
D) 35.8 J/ mole / K
✔ Correct Answer: 38.3 J/ mole / K
Exam Insight
Using the formula ΔS = nRln(V2/V1), for 2 moles of an ideal gas expanding from 10 dm³ to 100 dm³ at constant temperature (27°C), ΔS ≈ 38.3 J/K.