When an ideal gas undergoes unrestrained expansion, no cooling occurs because the molecules

Options

A. are above the inversion temperature
B. exert no attractive forces on each other
C. do work equal to loss in kinetic energy
D. collide without loss of energy

Explanation

To solve the question regarding the behavior of an ideal gas during unrestrained expansion, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Ideal Gas**:
- An ideal gas is a theoretical gas composed of many particles that are in constant random motion. The gas follows the ideal gas law (PV = nRT) and does not exhibit intermolecular forces.

2. **Unrestrained Expansion**:
- Unrestrained expansion refers to the process where a gas expands into a vacuum without any external pressure acting on it. This is also known as free expansion.

3. **Behavior of Molecules**:
- In the case of an ideal gas, the molecules do not interact with each other. There are no attractive or repulsive forces between the gas molecules. This is a key characteristic of ideal gases.

4. **Temperature Change During Expansion**:
- When an ideal gas expands freely, it does so without doing work on the surroundings and without heat exchange (adiabatic process). Since there are no intermolecular forces, the kinetic energy of the gas molecules remains constant.

5. **Conclusion**:
- Therefore, during unrestrained expansion of an ideal gas, no cooling occurs because the gas molecules do not exert any attractive forces on each other, and their kinetic energy remains unchanged.

### Final Answer:
No cooling occurs during the unrestrained expansion of an ideal gas because the molecules do not interact with each other (no attractive or repulsive forces).

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