Question

Assertion : Rate of reaction doubles when concentration of reactant is doubled if it is a first order reaction.

Reason: Rate constant also doubles.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (c) A is true but R is false

Explanation:

For first order reaction,

Rate₁ = k[A₁]

According to question,

[A₂] =  [2A₁]

:. Rate₂ = k[2A₁]

Rate₂ = 2 Rate₁

For a given reaction, rate constant is constant and independent of the concentration of reactant.