Question

Which among the following gases is difficult to liquify?

विकल्प

• Ammonia

• Carbon dioxide

• Oxygen

• Chlorine

Answer 1

Oxygen

Explanation:

When the temperature of gas falls below the critical temperature (T_c), it can be liquefied by cooling or applying pressure.

Gases with higher critical temperatures like Cl₂, NH₃, CO₂, SO₂ etc. can be liquefied easily by applying suitable pressure.

Gases like H₂, N₂, O₂ have low T_c, so it cannot be liquefied easily by pressure and cooling.