## deltaU=0

$\Delta U=q+w$

Ashley McClearnen 1B
Posts: 59
Joined: Fri Sep 28, 2018 12:26 am

### deltaU=0

Why is the change in internal energy equal to zero when the process is isothermal?

Karishma_1G
Posts: 67
Joined: Fri Sep 28, 2018 12:18 am

### Re: deltaU=0

Delta U is equal to zero for an isothermal reversible reaction because the heat that is entering the system is equal in magnitude to the work that the system is doing. For example, if -1000 J of work is being done during an isothermal reversible reaction, then 1000 J of heat is entering the system. Therefore, since internal energy = q (heat) + w (work), delta U is equal to zero. Hope that helps!

Posts: 91
Joined: Fri Sep 28, 2018 12:16 am

### Re: deltaU=0

Delta U is also 0 when there is no temperature change throughout the process.

Lisa Werner 2F
Posts: 72
Joined: Fri Sep 28, 2018 12:17 am

### Re: deltaU=0

delta u is 0 when q=-w