# What is Kep?

Dec 12, 2014

${K}_{e p}$ is the equilibrium product constant. It determines what you have more of, or what is "favored". If ${K}_{e q}$ is less than one, you have more reactants. If it is greater than 1 you have more products.

${K}_{e q}$ is calculated by taking the concentration of the products divided by the concentration of the reactants.

For the balanced reaction:

$a A + b B \to c C + \mathrm{dD}$

the equilibrium constant, ${K}_{e q}$is:

${K}_{e q} = \frac{{\left[C\right]}^{c} \cdot {\left[D\right]}^{d}}{{\left[A\right]}^{a} \cdot {\left[B\right]}^{b}}$

the above example is from: http://www.chemicool.com/

Note that the coefficients become exponents.

Also know that concentrations are never added or subtracted, only multiplied and divided.

The unit for concentration is usually moles/liter (Molarity)