A box with rigid instating walls is divided into two parts by a partition. An ideal gas occupies half the box and other half is completely evacuated. The partition is suddenly removed. Will there be any temperature change in the gas?

Explanation

The temperature of the gas remains unchanged. According to first law of thermodynamics `DeltaQ=DeltaU+PDeltaV` Here `DeltaQ=0` (adiabatic process) and P = 0, the gas expands in vacuum. Hence AU = 0. As the gas is ideal, there is no internal potential energy and hence the internal kinetic energy of the gas is constant.