Question

For the elementary reaction $M \rightarrow N$, the rate of disappearance of $M$ increases by a factor of 8 upon doubling the concentration of $M$. The order of the reaction with respect to $M$ is

(a) 4

(b) 3

(c) 2

(d) 1

Answer 1

Correct Option : (B)

Explanation—

$M \rightarrow N$

$r=k[\cdot M]^x $ ----(i)

$8 r=k[2 M]^x$ -----(ii)

On dividing eqn. (ii) by (i), we get

$8=(2)^x \Rightarrow(2)^3=(2)^x \Rightarrow x=3$