Question

The following plot of $t_{1/2}$ vs $(concentration{)}^{-2}$ corrosponds to:

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

Answer 1

The correct option is B third order

For nth order reaction, the relationship between the half life period and the concentration is $t_{1/2}=\frac{1}{k.a^{n-1}}.$
The graph shows that the half life period is directly proportional to $a^{-2}$.
$t_{1/2}=\frac{1}{k.a^2}$
Hence, $n-2=1$ or $n=3$.
Hence, the given reaction is of third order.