Which of the following statements is/are true?

Options

A. Hydrogen diffuses four times faster than oxygen.
B. The temperature of a real gas changes when it expands adiabatically in vacuum.
C. An ideal gas undergoes cooling effect when it suffers an adiabatic expansion in vacuum
D. The Joule-Thomson coeffcient `((dT)/(dP))_(H)` of an ideal gas is zero.

Explanation

To determine which of the statements provided in the question are true, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement A: Hydrogen diffuses four times faster than oxygen.**
- According to Graham's law of diffusion, the rate of diffusion of a gas is inversely proportional to the square root of its molecular mass.
- The molecular mass of hydrogen (H2) is 2 g/mol, and that of oxygen (O2) is 32 g/mol.
- Using Graham's law:
...