# Thermodynamics problem- isobaric process

• mrdith007
In summary, the problem involves an ideal monatomic gas going through a cycle on a PV diagram. The gas starts at state A with a volume of 0.0208 m3 and pressure of 1.22 × 10 5 Pa, and ends at state C with a volume of 0.0524 m3. Along the 305 ±1 K isotherm, the molar heat capacities are 20.8 J/mol · K and 12.5 J/mol · K. The task is to determine the heat added to the gas during process AB in units of J. The solution requires calculating the change in internal energy, which can be done using the equation \Delta U = C_V \Delta T for

## 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.
Answer in units of J

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

#### Attachments

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

## What is an isobaric process in thermodynamics?

An isobaric process is a thermodynamic process in which the pressure of a system remains constant while other variables, such as temperature and volume, may change. This type of process is commonly seen in open systems where the system is in contact with the surroundings and can exchange heat and work.

## What are some examples of isobaric processes?

Some examples of isobaric processes include boiling and condensation of a liquid, melting and solidification of a substance, and expansion and compression of a gas in a piston-cylinder system with a constant external pressure.

## How is work calculated in an isobaric process?

In an isobaric process, work is calculated as the product of the constant pressure and the change in volume of the system. This can be represented by the equation W = PΔV, where W is the work, P is the pressure, and ΔV is the change in volume.

## What is the first law of thermodynamics in an isobaric process?

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In an isobaric process, this can be written as ΔU = Q - PΔV, where ΔU is the change in internal energy, Q is the heat added, and PΔV is the work done by the system.

## How is heat calculated in an isobaric process?

In an isobaric process, heat is calculated as the product of the constant pressure and the change in temperature of the system. This can be represented by the equation Q = PΔT, where Q is the heat, P is the pressure, and ΔT is the change in temperature.