Ncert Exercises & Solutions

4.16 The rate constant for a first order reaction is 60 s–1. How much time will it take to reduce the initial concentration of the reactant to its 1/16th value?

It is known that,

$t = \frac{2.303}{K} \log \frac{{[R]}_{0}}{[R]}$
$= \frac{2.303}{60 s^{- 1}} \log \frac{1}{1_{16}}$
$= \frac{2.303}{60 s^{- 1}} \log 16$
$= 4.6 \times 10^{- 2} s (a p p r o x i m a t e l y)$