## Phase change

Novelpreet_Boparai1N
Posts: 19
Joined: Fri Jul 15, 2016 3:00 am

### Phase change

Say water is turned into vapor and you find the energy required to do so, would the reverse just be the negative of that energy?

Omeed_Partovi_1L
Posts: 12
Joined: Sat Jul 09, 2016 3:00 am

### Re: Phase change

Yes, every reaction's reversal is just the opposite sign of the original!

Joyce Zhang 2D
Posts: 24
Joined: Wed Sep 21, 2016 2:55 pm
Been upvoted: 1 time

### Re: Phase change

Provided an isolated system

Tycho_Meimban_2B
Posts: 31
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Phase change

To obtain the enthalpy change for the reverse for any process:

Δ H reverse process = - Δ H forward process

The enthalpy change for a reverse reaction is the negative of the enthalpy change for the forward reaction. Since we're reversing the reaction (from H2O(g) to H2O(l) ) we can use this formula above, to show the reverse reaction and the change in the enthalpy when the reverse reaction does occur.

Hope this helps!