Ideal Gas Questions

One kg of a diatomic gas is at a pressure of $8\times 10^4{\text{N/m}}^2$. The density of the gas is $4{\text{kg/m}}^3$. What is the energy of the gas due to its thermal motion?

Directions: Question numbers 28, 29 and 30 are based on the following paragraph. Two moles of helium gas are taken over the cycle ABCDA, as shown in the P – T diagram.

Two moles of helium gas are taken over the cycle $ABCDA$, as shown in the $P–T$ diagram. Assuming the gas to be ideal, the work done on the gas in taking it from $A$ to $B$ is: