Question

The rate constant for the first order reaction is $60s^{-1}$. How much time will it take to reduce the concentration of the reaction to $\frac{1}{16}$th value?

• A. $4.6\times {10}^{-2}s$
• B. $4.6\times {10}^{4}s$
• C. $4.6\times {10}^{2}s$
• D. $4.6\times {10}^{-4}s$

Answer 1

The correct option is A $4.6\times {10}^{-2}s$

$t=\frac{2.303}{k}log\frac{[A{]}_0}{\left[A\right]}$
$t=\frac{2.303}{60/s}log\frac{1}{1/16}$

$t=4.62\times {10}^{-2}s$

The time required to reduce the concentration of the reaction to 1/16th value is $4.62\times {10}^{-2}s$.