Question

What is the order of reaction-
$H_2 \; + Cl_2 \; \rightarrow 2HCl$

Answer 1

Hint : In the given question firstly we have to define what exactly is the order of reaction and how can we determine it and give the proper definition and the characteristics of it. And we also have to use the rate law to find the equation to find the order which is $r{\text{ }} = {\text{ }}k{\left[ A \right]^x}{\left[ B \right]^y}$ .

Complete Step By Step Answer:
The given question statement asks about the order of the reaction and the reaction preceding it. We have to provide the basic definition and the other important characteristics for the order of reaction along with the rate law.
The basic definition of the order of reaction:
So we can say that the order of reaction can be well defined as the power dependence of rate on the concentration of all reactants. For example, we can say that the reaction rate of a first-order reaction would therefore be dependent solely on the concentration of one of the species in the reaction.
Now we have to use the rate law to find the order:
In order to determine the reaction order, the power-law form of the rate equation is generally used. The expression of this form of the rate law is given by $r{\text{ }} = {\text{ }}k{\left[ A \right]^x}{\left[ B \right]^y}$ .
The reaction is a zero order reaction. The order of all photochemical reactions is zero as it does not depend upon the concentration of reactants.

Note :
In the expression described above, ‘r’ refers to the rate of reaction, ‘k’ is the rate constant of the reaction, [A] and [B] are the concentrations of the reactants. The exponents of the reactant concentrations x and y are referred to as partial orders of the reaction.