Problem 1.

How much work has been done by an ideal gas, when the temperature of 5 moles of the gas increases by 2 Kelvin in an isobaric process?

Solution:

The process is isobaric. It means that the pressure is constant. Let us assume that the pressure is equal to and the volume of the ideal gas changes from initial value to the final value . Then by definition, the work done by the gas is

or

But we know that this is an ideal gas. It means that the equation of state of the gas is the Ideal Gas Law. This Ideal Gas Law is valid for both initial and the final states of the gas. Then

where is the number of moles of the gas. Then the work done by the gas is

We know that . Then