Question

A first order reaction is $20\%$complete in 10 min. The specific rate constant of the reaction is_________ ($inmi{n}^{-1}$).

Answer 1

$k=\frac{2.303}{t}log\frac{a}{a-x}$
For $20\%$ completion,

$k=\frac{2.303}{10}log\frac{100}{80}=0.0223mi{n}^{-1}$