Question

Is it possible to cool a gas below absolute zero?

Answer 1

Absolute temperature:

• At a temperature of Zero Kelvin which is absolute temperature or absolute zero, it is believed that the gas reaches the conditions of zero volume and this condition is not possible practically that is why it is not possible to cool a gas below its absolute zero.
• Theoretically,$0\mathrm{K}$ is the least temperature where we can reach beyond this temperature we cannot reach.
• According to the ideal gas law equation-

$$\begin{gathered} \mathrm{PV}=\mathrm{nRT} \\ \mathrm{V}=\frac{\mathrm{nRT}}{\mathrm{P}} \\ \mathrm{if}\mathrm{we}\mathrm{are}\mathrm{consider}\mathrm{the}\mathrm{temperature}\mathrm{as}0\mathrm{K}\mathrm{then} \\ \mathrm{V}=0 \end{gathered}$$

At a temperature of $0\mathrm{K}$or absolute zero, gases are believed to occupy zero volume which is impossible to achieve practically.

Hence, it is not possible to cool the gas below the absolute zero temperature.