## Internal energy change, isothermal expansion

isochoric/isometric: $\Delta V = 0$
isothermal: $\Delta T = 0$
isobaric: $\Delta P = 0$

805303639
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### Internal energy change, isothermal expansion

I'm confused about why the change in internal energy for the isothermal expansion of a gas is 0. I understand that the kinetic energy of the system isn't changing due to the constant temperature. But wouldn't the potential energy of the gas decrease because of reduced intermolecular interactions/repulsions?

AKhanna_3H
Posts: 104
Joined: Wed Sep 18, 2019 12:19 am

### Re: Internal energy change, isothermal expansion

I believe it is because we are assuming an ideal gas, in which there are no intermolecular forces, so we only consider kinetic energy.