Question

A container holds gas at a constant pressure. A machine then expands the walls of the container from initial volume of 55 m3 to final volume of 93 m3. If the machine released 530 kJ of heat into the gas during this process, and the change in internal energy is determined to be 180 kJ, what is the pressure of the gas in the container?

Answer 1

Answer:

Given : P=200,000 Pa V

i

=1.0 m

3

V

f

=2.0 m

3

Work done by gas during expansion W=P(V

f

−V

i

)=200000×(2.0−1.0)=200,000 J

Amount of heat absorbed by the gas Q=+100,000 J

Using Q=ΔU+W

∴ 100000=ΔU+200000 ⟹ΔU=−100,000 J