## What is Qp?

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### What is Qp?

In the 1/20 lecture, Dr. Lavelle said that Qp = delta H. I am familiar with delta H but get confused about the Q. In equilibrium, Q is an equilibrium constant and P normally represents pressure but I am guessing it is used differently here. If someone could explain what Qp is in the context of enthalpy that would be very helpful!!!

Chem_Mod
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### Re: What is Qp?

The "q" we are talking about here is actually a lower-case "q", which represents heat. $q_{p}$ is q under constant pressure

Claire_Latendresse_1E
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### Re: What is Qp?

In equilibrium, Q represents the reactant quotient. In thermochemistry, the q used is lower case q. It represents heat (the energy transferred as a result of a change in temperature). Enthalpy, H, is the heat absorbed or lost in a reaction.
In the lecture, Dr. Lavelle said that qp = delta h under constant pressure. This means that when the pressure is constant, the heat transferred equals the enthalpy because no other forces act on the reaction to cause the temperature change.

kateraelDis1L
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### Re: What is Qp?

So lowercase q means heat transferred = enthalpy??

Jamie Wang 3C
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### Re: What is Qp?

Qp is the ratio that is similar to Kp when you don't know if the reaction is at equilibrium yet

Samudrala_Vaishnavi 3A
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### Re: What is Qp?

qp is basically representing the heat of the system so with a greater change in enthalpy or a positive change in enthalpy, the heat of the system increases, and it is an endothermic system. This is because the change in enthalpy usually refers to the system.

Return to “Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)”

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