### Isobaric

Posted:

**Wed Feb 13, 2019 10:06 am**I understand that isobaric means that pressure is constant and ΔP=0, but what equation does it play a role in?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=128&t=42169

Page **1** of **1**

Posted: **Wed Feb 13, 2019 10:06 am**

I understand that isobaric means that pressure is constant and ΔP=0, but what equation does it play a role in?

Posted: **Wed Feb 13, 2019 10:10 am**

For a constant pressure system, you would be able to use the equation W=-P*deltaV, as the P would be constant and thus can be multiplied by the change in volume to get the work done.

Posted: **Fri Feb 15, 2019 11:37 am**

Also in relation to the change in internal energy, heat under constant pressure is dH, which could help with the manipulation of dU=q+w.

Posted: **Fri Feb 15, 2019 11:50 am**

That also means that you must use the Cv value for ideal gases

MONOATOMIC: 3/2*R

LINEAR: 5/2*R

NONLINEAR: 7/2*R

MONOATOMIC: 3/2*R

LINEAR: 5/2*R

NONLINEAR: 7/2*R

Posted: **Fri Feb 15, 2019 1:36 pm**

it means that you can use the equation w=-PdeltaV

Posted: **Fri Feb 15, 2019 1:41 pm**

isobaric means that the volume is still changing so you can still calculate work

Posted: **Sat Feb 16, 2019 10:33 pm**

for a isobaric equation to find work you will want to use W= -p delta V.

Posted: **Tue Feb 19, 2019 12:46 pm**

Isobaric basically means there is no change in pressure, which means you can have work and heat changing your internal energy.

Posted: **Tue Feb 19, 2019 12:57 pm**

Isobaric means there's no change in pressure. As pressure is constant, use the formula w=-p*deltaV to find the work. Other words include Isochoric, which means there's no change in volume (AKA no work) and isothermic, which means no change in temperature (Delta U = 0).

Posted: **Tue Feb 19, 2019 5:23 pm**

If there is no change in pressure, as stated as ΔP=0, then there is value for the pressure to be plugged in the equation of w =-PΔV. If the value of pressure or the change in volume are not given, then you can use -Δn*R*T to find work. At a constant pressure,qp equal to ΔH. You can also find q with q=nCpΔT.

Posted: **Thu Feb 21, 2019 12:47 am**

To further complement the above responses, know that W = -PdeltaV is used to calculate work done by expansion against constant P. So since isobaric means constant pressure, this equation would be used.

Posted: **Thu Feb 21, 2019 1:26 am**

What would work most would be w= -pdeltav