Question

2A → B + C

Answer 1

Answer:

The correct answer is option 3.

Explanation:

2A → B + C

First trial ;

[A] = x , Rate of the reaction = R

Rate law of the reaction can be written as:

$R=k[x]^a$..[1]

Second trial ;

[A] = 3x , Rate of the reaction = R' = 9R

Rate law of the reaction can be written as:

$R'=k[3x]^a$

$9R=k[3x]^a$..[2]

[1] ÷ [2]

$\frac{R}{9R}=\frac{k[x]^a}{k[3x]^a}$

a = 2

Rate  of the reaction : $R=k[A]^3$

The order of the reaction is 2. This is because in the rate law expression the the power of the concentration of reactant A id 2.