JEE Main levelSingle correct optionDifficulty 2 of 3rg190
Which of the following is the correct expression for the inversion temperature of a van der Waals gas?
ATi=Rba
BTi=Rb2a
CTi=27Rb8a
DTi=2Rba
Answer: B
The Joule-Thomson coefficient of a van der Waals gas at low pressure is μ=Cp1(RT2a−b), which vanishes when T=2a/Rb. This is the inversion temperature, twice the Boyle temperature.