Law Of Mass Action - Practice Questions & MCQ

It was introduced by Guldberg and Waage. It states that “the rate at which a substance reacts is directly proportional to its active mass and the rate at which substances react together is directly proportional to the product of their active masses each raised to a power which is equal to the corresponding stoichiometric number the substance present in the chemical reaction".

If active masses of A, B, C and D are [A], [B], [C] and [D] respectively, then:

Rate of reaction of A ∝ [A]

Rate of reaction of B ∝ [B]

V₁ ∝ [A] [B] = K₁ [A][B]

V₂ ∝ [C] [D] = K₂ [C][D]

NOTE: Law of mass action is not applicable for solids as for them active mass is always one.