Question

An ideal gas cannot be liquified because

• A. Its critical temperature is always above $0^{\circ }\text{C}$.
• B. Its molecules are relatively smaller in size
• C. It solidifies before becoming a liquid
• D. Forces operating between its molecules are negligible

Answer 1

The correct option is D Forces operating between its molecules are negligible

Ideal gas cannot be liquefied because the intermolecular forces in ideal gas are negligible. In case of negligible intermolecular forces, the molecules will have free random motion which is possible in gaseous state. In liquid state, there is restricted motion of molecules since the molecules are held by intermolecular forces in liquid state which restricts their freedom of motion.