Question

In a first order reaction, 1010 % is complete Calculate:The half life of the reaction :

Answer 1

For 1st order reaction,
$K=\frac{2.303}{t}\log \frac{a}{a-x}$

$=\frac{2.303}{25}\log \frac{100}{100-10}$

$=0.0041245$

$\therefore$ Half life $T=\frac{0.693}{K}=\frac{0.693}{0.0042145}$
$T=164.43$ minutes.