Half-life of a reaction is found to be inversely proportional to the cube of initial concentration. The order of reaction is

Options

A. 5
B. 2
C. 4
D. 3

Answer

C

Explanation

The half-life period of `n^(th)` order reaction is
`t_(1//2)=(K)/(a^(n-1))`
a is the initial concentration of reactant.
`t_(1//2)prop(1)/(a^(3))" "thereforet_(1//2)=(K)/(a^(3))`
`(K)/(a^(n-1))=(K)/(a^(3))impliesa^(3)=a^(n-1)`
`impliesn-1=3impliesn=4`.
`therefore`The order of the reaction is 4.