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

Options

A. Both A and R are true and R is the correct explanation for A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

C

Explanation

For first order reaction
`"Rate"_(1)=k[A_(1)]`
`[A_(2)]=[2A_(1)]`
`"Rate"_(2)=k[2A_(1)]`
`"Rate"_(2)=kxx2" Rate"_(1)`
For a given reaction, rate constant is constant and independent of the concentration of reactant.