## Enthalpy

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

Clarice Chui 2C
Posts: 101
Joined: Fri Aug 30, 2019 12:16 am

### Enthalpy

What does it mean to say that enthalpy is additive because it is a state function? I know this is Hess's Law, but I'm confused conceptually.

Sidharth D 1E
Posts: 98
Joined: Sat Aug 24, 2019 12:17 am

### Re: Enthalpy

A state function is something where the path doesn't matter, only the initial and final state. The reason why it's important is that since the path doesn't matter, you can subtract, add, multiply, and divid state functions (entropy in this case) as necessary.

205007651
Posts: 53
Joined: Tue Nov 13, 2018 12:17 am

### Re: Enthalpy

It means that it will keep constant independent of the state of the system. So if it is liquid or solid it will stay the same enthalpy.

Gabriella Bates 2L
Posts: 113
Joined: Thu Jul 11, 2019 12:15 am

### Re: Enthalpy

This means that values of enthalpy can be added/subtracted to find the change in enthalpy, as we do in Hess's law. This is because enthalpy is a state function, so the path to get there does not matter.

peteryim
Posts: 54
Joined: Sat Sep 07, 2019 12:17 am

### Re: Enthalpy

State functions can be contrasted with path functions, where the pathway to the current state does matter. Compared to those, state functions do not rely on the pathway, so yes, can be added or subtracted simply.

Natalie Benitez 1E
Posts: 100
Joined: Fri Aug 02, 2019 12:15 am

### Re: Enthalpy

I remember that enthalpy(delta H) is the same as q, can someone explain this?