Question

For the first order reaction $A \rightarrow B$, the half life is $30 min$. The time taken for $75 \%$ completion of the reaction is min. (Nearest integer)
Given : $\log _g 2=0.3010$
$ \log 3=0.4771 $
$ \log 5=0.6989$

Answer 1

$t _{1 / 2}= T _{50}=30 \min$
$T _{75}=2 t _{1 / 2}=30 \times 2=60 \min$