Question

when applying pressure and reducing temperature gases con liquify?

Answer 1

Yes, gases can be liquefied by applying high pressure and low temperature. The compressibility of gases is attributed to the spaces between the particles of a gas. We know that the spaces between the constituent particles of a gas are very large and so gases have neither definite shape nor definite volume. On lowering the temperature, the motion of these particles reduces while on applying high pressure, the constituent particles come closer. This results in liquefaction of a gas.

Thus, a gas can be liquefied by increasing pressure and decreasing temperature.