## RXN constant P

$\Delta U=q+w$

Nahelly Alfaro-2C
Posts: 59
Joined: Wed Nov 15, 2017 3:04 am

### RXN constant P

When is the rxn constant P significant and insignificant? Why is knowing its significance important?

Celeste 1I
Posts: 44
Joined: Fri Sep 28, 2018 12:18 am

### Re: RXN constant P

I'm assuming you mean constant pressure. If something is under constant pressure that means the change in pressure is equal to 0 which means you can basically ignore it in the equation.

Laura Gong 3H
Posts: 89
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 1 time

### Re: RXN constant P

Knowing when the reaction is occurring under constant pressure can help you solve problems involving work. It can help you determine which equation to use (either w=-PdetlaV or w=-nRTln(Vf/Vi)).
Also at constant pressure we can determine that qp=deltaH.