# Thermodynamics problem- isobaric process

mrdith007

## Homework Statement

One mole of an ideal monatomic gas is taken through the cycle ABCA shown schematically
in the diagram. State A has volume 0.0208 m3 and pressure 1.22 × 10 5 Pa, and state C has volume 0.0524 m3 Process CA lies along the 305 ±1 K isotherm. The molar heat capacities for the gas are 20.8 J/mol · K and 12.5 J/mol · K.

Determine the heat Qab added to the gas during process AB.

I have attached an image with the graph. I am not sure if it is necessary. I got the correct answer to the first question (the new temp = 768.365 K)

## Homework Equations

W = p$$\Delta$$V
Q = $$\Delta$$U + W

## The Attempt at a Solution

I do not know how to calculate the U, which I think I need

## The Attempt at a Solution

#### Attachments

• graph.PNG
33.4 KB · Views: 746

$$\Delta U = C_V \Delta T$$ for an ideal gas.