Question

Which one of the following statements is correct about critical temperature?

• A. It is the temperature at which, saturated vapour pressure of a liquid equals the atmospheric pressure
• B. It is the temperature below which, evaporation of the liquid occurs very rapidly
• C. It is the temperature above which, a gas cannot be liquified.
• D. It is the temperature at which the states of solid, liquid and gas co- exit.

Answer 1

The correct option is C It is the temperature above which, a gas cannot be liquified.

Critical temperature is the temperature at which gas cannot be liquefied no matter what pressure be applied. At critical temperature, the properties of gas and liquid converge and heat of vaporization beyond this point becomes 0.