Question

(I) One liter of air is cooled at constant pressure until its volume is halved, and then it is allowed to expand isothermally back to its original volume. Draw the process on a PV diagram.

Short answer

The PV diagram of the process is shown below.

Step-by-step solution

Concepts

The process is called isobaric as the pressure is constant.

For the isothermal expansion, the gas follows Boyle's law.

Given data

The initial volume of the gas is 1 L.

PV diagram 

The volume of the gas becomes 0.5 L at the end of the first compression.

The PV diagram of the process is shown below.

Here, the pressure of the gas decreases during the isothermal expansion.