Question

Statement - I: For the reaction given below:

The molecularity of the first step is 1 and the second step is 2.

$2O_3\left(g\right)\to 3O_2\left(g\right)$

Step 1: $O_3\left(g\right)\rightleftharpoons O_2\left(g\right)+O\left(g\right)$

Step 2: $O_3\left(g\right)+O\stackrel{slow}{\to }2O_2\left(g\right)$

Statement - II: O(g) is an intermediate. The rate of reaction is $K\left[O_3{]}^2\right[O_2{]}^{-1}$ and the order of the reaction is 1.

• A. Statement I and statement II are true and statement II is the correct explanation of statement I.
• B. Statement I and statement II are true but statement II is not the correct explanation of statement I.
  
• C. Statement I is true and statement II is false.
• D. Statement I is false and statement II is true.
  

Answer 1

The correct option is B Statement I and statement II are true but statement II is not the correct explanation of statement I.

Molecularity is the number of molecules of reactants that collide to form products.

The molecularties of steps 1 and 2 are 1 and 2 respectively as one and two molecules participate to give products.

From, the rate of the reaction, the order of the reaction can be calculated as $2-1=1$.
The concentration of the intermediate does not appear in the rate law expression.

Statement I and statement II are true but statement II is not the correct explanation of statement I.

Option B is correct.