_{eq}) that defines the relationships between the concentrations of products and reactants.

K

_{eq}= (concentration of each product raised to a power of the coefficient of the corresponding product)÷ (concentration of each reactant raised to the coefficient of the corresponding reactant).

To make it more clear,

(where the lower case letters are the coefficients)

Since k

**What k**

_{eq }tells:Since k

_{eq}is products over reactants, the larger it is, we know that the more products there are in the equilibrium (and vice versa). So a large k

_{eq}(e.g., 1000000) means that the reaction is close to completion, and a very small k

_{eq }(e.g., 0.00000001) means that the reaction barely occurs.