Question

Choose the odd one out for ideal gas

• A. The molecules of ideal gas do not obey Newton's laws of motion
• B. An ideal gas consists of a large number of unidentical molecules
• C. Ideal gases have perfectly elastic collisions
• D. The molecules do not move in random motion

Answer 1

The correct option is C

Ideal gases have perfectly elastic collisions

The explanation for the correct answer:

In the case of Option C,

1. An ideal gas is made up of many indistinguishable molecules. In various aspects, ideal gas differs from natural gas.
2. The volume maintained by the molecules is small in comparison to the volume filled by the gas.
3. Only during collisions do the molecules experience forces; any collisions are completely elastic and require a small amount of time.

The explanation for the incorrect answer:

In the case of Option A,

1. The molecules move randomly, following Newton's rules of motion in an ideal gas.
2. The molecules of an ideal gas are in constant random motion.

In the case of Option B,

1. Many gases are nearly ideal near room temperature and atmospheric pressure and exhibit this connection fairly well.
2. As pressure and temperature rise, all gases vary from the ideal.
3. An ideal gas consists of a large number of identical molecules.

In the case of Option D,

1. An ideal gas is a theoretical gas that does not exist in reality but is believed to exist in order to simplify calculations.
2. The molecules of an ideal gas are in constant random motion.

Therefore, option C is the correct choice.