Expansion Against a Vacuum


and

Moderators: Chem_Mod, Chem_Admin

Michelle Wang 4I
Posts: 63
Joined: Fri Sep 28, 2018 12:27 am

Expansion Against a Vacuum

Postby Michelle Wang 4I » Wed Feb 13, 2019 1:20 am

How come when a gas expands against a vacuum work = 0? What does delta S, delta U, and q equal for this situation as well?

Gary Qiao 1D
Posts: 66
Joined: Fri Sep 28, 2018 12:26 am

Re: Expansion Against a Vacuum

Postby Gary Qiao 1D » Wed Feb 13, 2019 4:02 am

When the gas is expanding in a vacuum, there is nothing to oppose the gas (free expansion), making the work = 0. In a vacuum, there is also no change in temperature or heat change, making delta U = 0, thus q= 0. delta S in free expansion would still be equal to nRln(V2/V1).

MackenziePerillo-1L
Posts: 31
Joined: Fri Sep 28, 2018 12:19 am

Re: Expansion Against a Vacuum

Postby MackenziePerillo-1L » Sat Feb 16, 2019 12:56 pm

would this be an example of an irreversible system?

Fionna Shue 4L
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: Expansion Against a Vacuum

Postby Fionna Shue 4L » Wed Feb 20, 2019 6:07 pm

Yes, this would be an irreversible system

Jason Ye 2I
Posts: 33
Joined: Fri Sep 28, 2018 12:22 am

Re: Expansion Against a Vacuum

Postby Jason Ye 2I » Thu Feb 21, 2019 12:20 am

Yes that is an irreversible system.


Return to “Calculating Work of Expansion”

Who is online

Users browsing this forum: No registered users and 1 guest