Clarification
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 7
- Joined: Wed Nov 16, 2016 3:03 am
Clarification
I am a little confused about the relationship between heat transfer and enthalpy: Is Heat Transfer the transference of energy, and enthalpy is heat transfer at a constant pressure?
-
- Posts: 33
- Joined: Tue Nov 15, 2016 3:00 am
Re: Clarification
I had a similar question and found this link helpful: https://chemistry.stackexchange.com/que ... and-heat-q
It says, "Enthalpy and heat are entirely different things.
Enthalpy is a function of state. If you know the state of a system, you know its enthalpy. If you know the starting and ending states of a process, you can find the enthalpy change.
Heat, on the other hand, is an inexact differential. Knowing the initial and final states of a process is not enough information to tell you the heat transfer. Instead, the heat transfer depends on the particular path taken between the states."
It says, "Enthalpy and heat are entirely different things.
Enthalpy is a function of state. If you know the state of a system, you know its enthalpy. If you know the starting and ending states of a process, you can find the enthalpy change.
Heat, on the other hand, is an inexact differential. Knowing the initial and final states of a process is not enough information to tell you the heat transfer. Instead, the heat transfer depends on the particular path taken between the states."
-
- Posts: 38
- Joined: Thu Jul 13, 2017 3:00 am
Re: Clarification
While enthalpy is a state function, heat is not. So, you can calculate enthalpy by simply doing (final-initial). On the other hand, heat is not a state function. Heat is defined by the path it takes to get from point 1 to point 2, which is why we can't treat it like a state function.
-
- Posts: 53
- Joined: Fri Sep 29, 2017 7:04 am
Re: Clarification
Yeah, for heat transfer you need to know every single individual step that is involved in the reaction. However, for enthalpy you only need to know the initial and final amounts since it is a state function; it doesn’t matter the pathway that is taken in order to reach the final amount.
Return to “Phase Changes & Related Calculations”
Who is online
Users browsing this forum: No registered users and 12 guests