Question

$t_{1/2}v/s\frac{1}{a^2}$ is straight line graph then determine the order of a reaction:

• A. zero order
• B. first order
• C. second order
• D. third order

Answer 1

The correct option is D third order

In general for an $n^{th}$ order of a reaction, the half life period is given by,

$t_{1/2}\propto \frac{1}{a^{n-1}}$, $a$= initial concentration; $n$= order of reaction

Given, $t_{1/2}$ $v/s$ $1/a^2$ i.e, $n-1=2,n=3$

$\therefore t_{1/2}$= (constant)$\frac{1}{a^2}$ is a straight line.

for $n=3$ i.e, for Third order reaction.