Question

A gas is kept in a rigid container and 100 J of heat is supplied to it. What is the work done by the gas and the change in the internal energy of the gas?​

Answer 1

Work done: 0 J

Change in internal energy: +100 J

Step-by-step explanation:

- The work done by the gas is given by:

`W=p\Delta V`

where

p is the gas pressure

`\Delta V` is the change in volume of the gas

Since the gas is kept in a rigid container, its volume is fixed, so there is no change in volume: therefore,
`\Delta V=0` and the work done is zero as well:

`W=0`

- The change in internal energy of the gas is given by the 1st law of thermodynamics:

`\Delta U=Q-W`

where Q is the heat supplied to the gas. Since W=0 and Q=+100 J, then the change in internal energy of the gas is

`\Delta U=+100 J+0=+100 J`