# Question #c1a9b

Nov 10, 2015

#### Answer:

$\Delta {H}_{r e a c t i o {n}^{\theta}}$ = $\Sigma {\Delta}_{f} {\left(P r o \mathrm{du} c t s\right)}^{\theta}$ - $\Sigma {\Delta}_{f} {\left(R e a c \tan t s\right)}^{\theta}$

#### Explanation:

Hess's Law relates to the conservation of energy (the first law of Thermodynamics). It just states that there is a constant amount of energy that is never arbitrarily created or destroyed in a chemical reaction. Hess's law is simply the summation of the energies of the products subtract the summation of energies of the reactants.

$\Delta {H}_{r e a c t i o {n}^{\theta}}$ = $\Sigma {\Delta}_{f} {\left(P r o \mathrm{du} c t s\right)}^{\theta}$ - $S i g m {\Delta}_{f} {\left(R e a c \tan t s\right)}^{\theta}$

There is a list of $\Delta H$ that will tell you all of the energies that common compounds have. When given an equation simply add the energies of one side of the reaction equation and subtract them from the sum of the other side.