The half-life of the reaction $$X \to Y,$$ following first order kinetics, when the initial concentration of $$X$$ is $$0.01\,mol\,{L^{ - 1}}$$ and initial rate is \[0.00352\,mol\,{{L}^{-1}}\,{{\min }^{-1}}\] will be
A.
$$19.69\,\min .$$
B.
$$1.969\,\min .$$
C.
$$7.75\,\min .$$
D.
$$77.5\,\min .$$
Answer :
$$1.969\,\min .$$
Solution :
$$\eqalign{
& \frac{{dx}}{k} = k\left[ X \right]\,{\text{(For a first order reaction)}} \cr
& 0.00352 = k \times 0.01 \Rightarrow k = 0.352 \cr
& {t_{\frac{1}{2}}} = \frac{{0.693}}{k} = \frac{{0.693}}{{0.352}} = 1.969\,\min . \cr} $$
Releted MCQ Question on Physical Chemistry >> Chemical Kinetics
Releted Question 1
If uranium (mass number 238 and atomic number 92) emits an $$\alpha $$ -particle, the product has mass no. and atomic no.