Question

Definition of rate law.

Answer 1

Hint: As we know that rate law can be described as the law which is used for studying the relationship between the rate of reaction and the concentration of the reactants participating in that reaction. So in this question we have to put down the information regarding the rate law.

Complete answer:
Let us understand the concept of rate law in chemistry as follows:-
-Rate law: It is the mathematical relationship of reaction rate with the concentrations of the reactants participating in it. This relationship may depend more importantly on the concentration of one particular reactant. Also the resulting rate law may include some, all or none of the reactant species involved in that reaction.
-For example, let us take a reaction as follows:-
$aA+bB\to cC$
The rate law for the above reaction can be expressed as:
Rate = $k{{[A]}^{y}}{{[B]}^{z}}$
Where,
k = it is the proportionality constant which is known as ‘rate constant’ for that reaction.
[A], [B] = these represent the concentrations of the reactants involved in the reaction.
y, z = these represent the reaction order with respect to their particular reactants (also referred as partial orders).
-Note that the expression of the rate law for a specific reaction can only be determined experimentally because the rate law expression cannot be obtained from the balanced chemical equation as the partial orders of the reactants are not necessarily equal to the stoichiometric coefficients.

Note:
-The partial order of the reactants is equal to stoichiometric coefficients only in case of elementary reactions, not in complex reactions which consist of various steps.
-Also understand the chemical kinetics chapter to solve the questions related to rate laws and rate of the reaction.