Question

A first order reaction takes 10 minute for 30% completion. Find rate constant of the reaction.

विकल्प

• 0.0177 minute^-1

• 0.0357 minute^-1

• 0.0526 minute^-1

• 0.0713 minute^-1

Answer 1

0.0357 minute^-1

Explanation:

Given, a = 100, x = 30, when t = 10 min.
Substituting these values in the first order integrated law,
\[\mathrm{k}=\frac{2.303}{\mathrm{t}}\log_{10}\frac{\mathrm{a}}{\mathrm{a}-x}\mathrm{,we~get}\]
\[\mathrm{k}=\frac{2.303}{10}\log_{10}\frac{100}{100-30}\]
\[=\frac{2.303}{10}\log_{10}\frac{10}{7}\]
\[=\frac{2.303}{10}(\log_{10}10-\log_{10}7)\]
\[\begin{aligned} & =0.2303\times(1-0.845) \\ & =0.2303\times0.155 \\ & \mathrm{k}=0.03569\mathrm{~min}^{-1}\approx0.0357\mathrm{~minute}^{-1} \end{aligned}\]