Question

For a second order reaction, $2A \rightarrow $ Products, a plot of $\log t_{1 / 2}$ vs $\log a$ (where, $a$ is initial concentration) will give an intercept equal to

• A. $\frac{1}{k}$
• B. $log \left(\frac{1}{2 k}\right)$
• C. $log k$
• D. $log \left(\frac{1}{k}\right)$

Answer 1

Answer: (D)

Kinetic equation for second order reaction is
$k=\frac{1}{t}\left[\frac{1}{\left(\right. a - x \left.\right)} - \frac{1}{a}\right]$
when $x=\frac{a}{2}$
$t=t_{1 / 2}$

So $t_{1 / 2}=\frac{1}{k}\times \frac{1}{a}$
$log t_{1 / 2}=-log ⁡ k-log ⁡ a$
Here intercept = $log \left(\frac{1}{k}\right)$