## Hess's Law

Renee Delamater 2H
Posts: 31
Joined: Wed Nov 16, 2016 3:02 am

### Hess's Law

What exactly does Hess's Law state?

Matthew Lin 2C
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am

### Re: Hess's Law

Hess's Law states (according to the book) that "the overall reaction enthalpy is the sum of the reaction enthalpies of the
steps into which the reaction can be divided." For example, if you the enthalpies of two reactions that make up one overall reaction, you can find the enthalpy of the overall reaction by adding the enthalpies of the two reactions. Let me know if you need further clarification about it!

Renee Delamater 2H
Posts: 31
Joined: Wed Nov 16, 2016 3:02 am

### Re: Hess's Law

Thanks! So how does this equation and idea relate to specific heat? Is specific heat involved in the equation to find enthalpy because it is needed in each step of a specific reaction?

Dang Lam
Posts: 55
Joined: Thu Jul 27, 2017 3:01 am

### Re: Hess's Law

i don't think it has to do with specific heat.

Sally Nason - 1K
Posts: 40
Joined: Fri Sep 29, 2017 7:05 am

### Re: Hess's Law

Since enthalpy is a state function, it doesn't matter what path is taken to the final point, the only values that matter are final and initial. That is why you can "skip" intermediate steps by adding equations.

Michael Lee 2I
Posts: 51
Joined: Fri Sep 29, 2017 7:05 am

### Re: Hess's Law

The only thing you really need to know, since the path taken does not matter, is final state - initial state.

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