## free expansion

$\Delta U=q+w$

paytonm1H
Posts: 74
Joined: Fri Sep 28, 2018 12:18 am

### free expansion

why, in free expansion, are work and heat transfer both equal to zero?

skyeblee2F
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: free expansion

Free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber. Because it's insulated, there is no change in temperature and q=0. Because there is no external pressure and gas is moving freely, w=0 too.

Roberto Gonzalez 1L
Posts: 39
Joined: Fri Sep 28, 2018 12:17 am

### Re: free expansion

For free expansion there is no acting external pressure as it is in a vacuum and therefore no work being done. The insulation accounts for a lack of transfer of heat.