Law of Mass Action

The law of mass action was given by two Norwegian Chemists Gulberg and Waage in 1867 which states,

 “At constant temperature the rate of a chemical reaction is directly proportional to the product of the molar concentrations of reactants each term raised to the power equal to the Stoichiometric co-efficient as represented by balanced chemical equation.”

Let us consider a chemical reaction

aA    +   bB    →  Product.

Where a, b are stoichiometric co-efficients.

Then,

According to law of mass action,

Rate of reaction, (r) µ  [A]^a[B]^b

Where [A] and [B] are molar concentration of A and B.

\        r   =   K[A]^a[B]^b