H and q

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Abigail Sanders 1E
Posts: 112
Joined: Wed Sep 11, 2019 12:16 am

H and q

Postby Abigail Sanders 1E » Fri Jan 31, 2020 2:42 am

How are delta H and q different in terms of heat? In the homework questions these variables are used interchangeably, is there a way to distinguish when you use one or the other and what does each mean?

Connie Chen 1E
Posts: 51
Joined: Mon Jun 17, 2019 7:24 am

Re: H and q

Postby Connie Chen 1E » Fri Jan 31, 2020 10:24 am

Delta H refers to the total heat in a system whereas q is the heat that is being transferred. Delta H is equal to q when the pressure is constant, but if the pressure changes, then they are not the same.

Ryan Yoon 1L
Posts: 55
Joined: Mon Jul 01, 2019 12:15 am

Re: H and q

Postby Ryan Yoon 1L » Fri Jan 31, 2020 10:27 am

delta h is the amount of heat released or absorbed at a constant pressure, which is also enthalpy. whereas q is the heat being transferred. they are equal to each other if they are at the same pressure.

Sydney Myers 4I
Posts: 100
Joined: Fri Aug 09, 2019 12:17 am

Re: H and q

Postby Sydney Myers 4I » Fri Jan 31, 2020 11:31 am

The definition of enthaply is heat at a constant pressure. Q is heat, so the two are highly related. You can tell if delta H and q are the same if q has a subscript of p, meaning that it's the heat at a constant pressure.

Jocelyn Thorp 1A
Posts: 103
Joined: Wed Sep 18, 2019 12:20 am

Re: H and q

Postby Jocelyn Thorp 1A » Sat Feb 01, 2020 10:46 pm

Connie Chen 1E wrote:Delta H refers to the total heat in a system whereas q is the heat that is being transferred. Delta H is equal to q when the pressure is constant, but if the pressure changes, then they are not the same.

this explanation makes a lot of sense, thanks!

Jesse H 2L
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Joined: Fri Aug 09, 2019 12:17 am
Been upvoted: 1 time

Re: H and q

Postby Jesse H 2L » Sun Feb 02, 2020 12:09 am

delta h and q are the same at constant pressure.

Megan Cao 1I
Posts: 103
Joined: Sat Sep 07, 2019 12:18 am

Re: H and q

Postby Megan Cao 1I » Sun Feb 02, 2020 10:03 am

delta H is the enthalpy of the reaction, which is the total heat of the system. q is the heat that is transferred. when pressure's constant, delta h = qp.

Jasmine 2C
Posts: 184
Joined: Wed Sep 18, 2019 12:18 am

Re: H and q

Postby Jasmine 2C » Sun Feb 02, 2020 11:00 am

q equals delta H when pressure is constant


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