Question
The rate constant for a first order reaction is \[2\times {{10}^{-2}}\,{{\min }^{-1}}.\] The half-life period of reaction is
A.
$$69.3\,\min .$$
B.
$$34.65\,\min .$$
C.
$$17.37\,\min .$$
D.
$$3.46\,\min .$$
Answer :
$$34.65\,\min .$$
Solution :
$$\eqalign{
& {t_{\frac{1}{2}}} = \frac{{0.693}}{k} \cr
& \,\,\,\,\,\,\, = \frac{{0.693}}{{2 \times {{10}^{ - 2}}}} \cr
& \,\,\,\,\,\,\, = 34.65\,\min . \cr} $$