## Isolated System Energy Change

Vivian Chen 3A
Posts: 10
Joined: Fri Sep 26, 2014 2:02 pm

### Isolated System Energy Change

If an isolated system has +15kJ, after a certain amount of time, how much energy would the system have? Would the amount of energy remain constant?

Neil DSilva 1L
Posts: 70
Joined: Fri Sep 26, 2014 2:02 pm

### Re: Isolated System Energy Change

By definition, energy and matter cannot be transferred into/out of an isolated system, so whatever energy is in the system remains constant. Therefore, if an isolated system has +15 kJ of energy at some point in time, it will have +15kJ at any other time. Yes, the amount of energy would remain constant and $\Delta U = 0$ (change in interal energy is 0).

Chem_Mod
Posts: 19559
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 885 times

### Re: Isolated System Energy Change

Yes, Neil's explanation is spot on.