Embibe Experts Solutions for Chapter: Chemical Kinetics, Exercise 1: WBJEE 2020

Consider the following two first order reactions occurring at $298 \mathrm{K}$ with same initial concentration of $\mathrm{A}:$

(1) $\mathrm{A}\to \mathrm{B};$ rate constant, $\mathrm{k}=0.693 {\min }^{-1}$

(2) $\mathrm{A}\to \mathrm{C};$ half-life, ${\mathrm{t}}_{1/2}=0.693 \min$

Choose the correct option.

The half-life period of ${}_{53}{125}^{}$ is 60 days. The radioactivity after 180 days will be

The half-life of ${\mathrm{C}}^{14}$ is $5760$ years. For a $200\mathrm{mg}$ sample of ${\mathrm{C}}^{14},$ the time taken to change to $25\mathrm{mg}$ is

For a reaction $2\mathrm{A}+\mathrm{B}\to \mathrm{P},$ when concentration of $\mathrm{B}$ alone is doubled, ${\mathrm{t}}_{1/2}$ does not change and when concentrations of both $\mathrm{A}$ and $\mathrm{B}$ is doubled, rate increases by a factor of $4.$ The unit of rate constant is,

The kinetic study of a reaction like $\mathrm{A}\to \mathrm{P}$ at $300 \mathrm{K}$ provides the following curve, where concentration is taken in mol ${\mathrm{dm}}^{-3}$ and time in min.

Identify the correct order $\left(\mathrm{n}\right)$ and rate constant $\left(\mathrm{k}\right)$