Gases possess characteristic critical temperature which depends upon the magnitude of intermolecular forces between the gas particles. Critical temperatures of ammonia and carbon dioxide are 405.5 K and 304.10 K respectively. Which of these gases will liquify first when you start cooling from 500 K to their critical temperature ?

Explanation

We have read that a gas gets liquefied when cooled below its critical temperature `(Tc)` . Upon cooling from 500 K, the critical temperature of ammonia `(405.5 K)` will be attained first. It will get liquefied first as compared to carbon dioxide for which critical temperature `(304.15 K)` is attained on further cooling.