Question

From different sets of data of $t_{1/2} $ at different initial concentration say $'a' $ for a given reaction, the product $[ t_{1/2} \times a] $ is found to be constant. The order of reaction is

• A. $ 2$
• B. $ 1$
• C. zero
• D. $ 3$

Answer 1

Answer: (A)

For zero order, $t_{1/2}= \frac {a}{2k} $
So, $t_{1/2} \times a = \frac {a^2}{2k} $ is not a constant.
For $ 1^{st} $ order, $ t_{1/2} $ is constant so $ t_{1/2} \times a$ is not constant
For $2^{nd} $ order, $ t_{1/2} = \frac {I}{a\times k} $
$t _{1/2}\times a = k$ is constant.