Question

A mixture of gas expands from 0.03m³ to 0.06m³ at constant pressure of 1MPa & absorbs energy of 84 J. Calculate the change in internal energy?

Answer 1

To calculate the change in internal energy, use the equation ΔU = Q - W, where Q is the heat transferred to the gas and W is the work done by the gas. Calculate the work done by the gas using the equation W = PΔV and then find the change in internal energy.

Step-by-step explanation:

The change in internal energy of a gas can be calculated using the equation:

ΔU = Q - W

Where:

• ΔU is the change in internal energy
• Q is the heat transferred to the gas
• W is the work done by the gas

In this case, the heat transferred to the gas is given as 84 J and the work done by the gas can be calculated using the equation:

W = PΔV

Where:

• P is the pressure
• ΔV is the change in volume

Using the given values, we can calculate the work done by the gas and then find the change in internal energy.

Answer 2

Answer:54 kj

Explanation:P1 = P2 = 1000 kPa

1Q2 = 84 kJ

1W2 = P1 (V2 – V1)

= 1000 (0.06 – 0.03) = 30 kJ

1Q2 = 1W2 + 1U2

U2 – U1= 1Q2 – 1W2 = 84 – 30 = 54 kJ