q=∆H clarification  [ENDORSED]

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Lindsay H 2B
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q=∆H clarification

Postby Lindsay H 2B » Tue Jan 09, 2018 11:14 am

Example 8.6 in the book and question 8.31 both ask for a change in energy at (a) constant pressure and (b) constant volume. Does this mean that only part (a) is considered finding the enthalpy, since the enthalpy definition Dr. Lavelle gave us in lecture was the change in heat at a constant pressure?

Chem_Mod
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Re: q=∆H clarification

Postby Chem_Mod » Tue Jan 09, 2018 11:51 am

Correct.

I will discuss this more in class when we cover:

Michelle Dong 1F
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Re: q=∆H clarification

Postby Michelle Dong 1F » Tue Jan 09, 2018 5:38 pm

Constant volume would mean that work (w) equals 0 because of the equation w= external pressure * change in volume. This means that the change in energy at constant volume would only equal q (delta U = q), which is the amount of heat given off or absorbed in a reaction.

Chem_Mod
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Re: q=∆H clarification  [ENDORSED]

Postby Chem_Mod » Tue Jan 09, 2018 6:31 pm

Correct.

To be precise:

I will cover all of this in class next week.

You are all ahead of the game. :-)


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