state Def law of mass action
Answers
Answer:
Law of mass action is the proposition that the rate of chemical reaction is directly proportional to the product of the activities or concentration of the reactants.
Answer:
Law of Mass Action
Guldberg and Waage put forward a relationship in 1867 between the rate of reaction and the molar concentration of reactants.The relationship is known as Law of mass action.
It states that -
The rate at which a substance reacts is proportional to its active mass and rate of a chemical reaction is directly proportional to the product of the active masses of the reactants.
Active mass of a substance means the molar concentration that is number of moles per litre of the reacting substance.The active mass of a substance, A, is expressed by [A] .
To explain the law, consider a simple reaction :
A ------------------> Products
In this reaction, only a single substance undergoes the reaction and only one molecule of it is involved in the equation for the reaction. Thus, rate of reaction will depend only on the concentration of A. Mathematically, it may be expressed as -
Rate of reaction ∝ [A]
or,
CA (C subscript A) = k[A]
Where [A] or CA(C subscript A) is the molar concentration of active mass of A and k is a proportionality constant known as rate constant. The rate constant is also called velocity constant velocity coefficient of specific reaction rate.
Similarly, for a reaction which involves two reactants A and B:
A + B ------------------> products
- Rate ∝ [A][B] = k[A][B]
For a general reaction,
aA + bB + cC + ......... -----------> Products
- Rate of reaction = k[A]^a × [B]^b × [C]^c
Thus, the law of mass action may be restated in more precise form as :-
The rate of a chemical reaction at any particular time at given temperature, us proportional to the product of the concentrations of reactants with each concentration term raised to the power equal to the number of molecules of the respective reactant taking part in the reaction.