## Delta H v. q

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

### Delta H v. q

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

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

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

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

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

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

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