Question

In the inversion curve for a gas, in the region of cooling:

• A. Joule-Kelvin coefficient is negative
• B. Joule-Kelvin coefficient is positive
• C. Joule-Kelvin coefficient is zero
• D. None of the three

Hint:

A positive Joule-Kelvin coefficient means the gas cools during expansion, which is used in liquefaction processes.

Answer 1

The Correct Option is B

The Joule-Kelvin coefficient \( \mu_J \) is given by:
\[ \mu_J = \left( \frac{\partial T}{\partial P} \right)_H \] - Cooling occurs when \( \mu_J>0 \) (i.e., temperature decreases as pressure decreases).
- Heating occurs when \( \mu_J<0 \) (temperature increases as pressure decreases).
- At the inversion temperature, \( \mu_J = 0 \).