Delta H v. q

Moderators: Chem_Mod, Chem_Admin

LNgo 1G
Posts: 100
Joined: Sat Aug 24, 2019 12:16 am

Delta H v. q

Postby LNgo 1G » Thu Jan 30, 2020 9:26 am

What is the difference between delta H and q?

Izzie Capra 2E
Posts: 103
Joined: Sat Sep 07, 2019 12:19 am

Re: Delta H v. q

Postby Izzie Capra 2E » Thu Jan 30, 2020 9:53 am

I believe that q is simply the heat that can be measured in a transfer. Enthalpy (delta H) is the total heat content in a system. It is energy, kind of like its potential energy RELATING to heat.

Abby Soriano 1J
Posts: 103
Joined: Sat Aug 24, 2019 12:16 am

Re: Delta H v. q

Postby Abby Soriano 1J » Thu Jan 30, 2020 11:24 am

Do you know why or how delta H is equal to qp? What about the constant pressure makes the two equal?

Angela Prince 1J
Posts: 102
Joined: Sat Aug 24, 2019 12:17 am

Re: Delta H v. q

Postby Angela Prince 1J » Thu Jan 30, 2020 11:35 am

Delta H is equal to q only when the gas is at a constant pressure. By definition, enthalpy (deltaH) is the amount of heat released/absorbed at a CONSTANT PRESSURE, so the heat required to change temp of gas at a constant pressure is the same as enthalpy.

Abby Soriano 1J
Posts: 103
Joined: Sat Aug 24, 2019 12:16 am

Re: Delta H v. q

Postby Abby Soriano 1J » Thu Jan 30, 2020 11:36 am

Angela Prince 1J wrote:Delta H is equal to q only when the gas is at a constant pressure. By definition, enthalpy (deltaH) is the amount of heat released/absorbed at a CONSTANT PRESSURE, so the heat required to change temp of gas at a constant pressure is the same as enthalpy.


So does that mean that the same does not hold for qv?

ValerieChavarin 4F
Posts: 99
Joined: Wed Sep 18, 2019 12:18 am

Re: Delta H v. q

Postby ValerieChavarin 4F » Thu Jan 30, 2020 4:11 pm

q refers to the energy, as heat, transferred due to a change in temperature. is the heat transferred at constant pressure


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

Who is online

Users browsing this forum: No registered users and 3 guests