Question

7. Which of the given gas is expected to have lowest criti-
cal temperatures ?
(a) NH3
(b) He
(c) SO2
(d) CH4​

Answer 1

Answer:

Gases can be converted to liquids by compressing the gas at a suitable temperature. However, they become more difficult to liquefy as the temperature increases because the kinetic energies of the particles that make up the gas also increase. At the critical temperature they cannot longer be liquified.

Critical Temperature: The temperature which above, a substance can not exist as a liquid, no matter how much pressure is applied. Every substance has a critical temperature.

Critical Pressure: The pressure required to liquify a substance vapor at its critical temperature

Critical point: The end point of the pressure-temperature curve that designates conditions under which a liquid and its vapor can coexist. At higher temperatures, the gas cannot be liquefied by pressure alone. At the critical point, defined by the critical temperature Tc and the critical pressure pc, phase boundaries vanish.

Explanation: