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### Qv vs Qp

Posted: Thu Jan 30, 2020 11:44 am
What is the difference between qv and qp?

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 12:00 pm
qv implies constant volume, whereas qp is constant pressure.

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 12:37 pm
Both of these are used to find enthalpy/delta H but also find change in internal energy which is q + w. Therefore, q can either be qp or qv depending on the given conditions.

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 12:54 pm
Sidharth D 1E wrote:Both of these are used to find enthalpy/delta H but also find change in internal energy which is q + w. Therefore, q can either be qp or qv depending on the given conditions.

Enthalpy/delta H is equal to qp, the amount of heat released or absorbed at a constant pressure. Using qv implies that the change in the internal energy (U) equals qv. The work term w drops out of U = q + w under conditions of constant volume.

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 1:35 pm
q at constant volume and q at constant pressure

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 5:06 pm
Both represent heat energy of deltaH, but one is used when the volume is constant and the pressure changes (Qv) and the other is when the pressure is constant but the volume is changing (Qp).

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 5:13 pm
qv is constant volume and qp is constant pressure

### Re: Qv vs Qp

Posted: Thu Jan 30, 2020 8:42 pm
Qv is when there's constant volume while Qp is constant pressure