Chemistry - Chemical Kinetics Question with Solution | TestHub

Given, for two first order reactions. $$A\to Bk=0.693{\min }^{-1}...(1)$$ and $$A\to C,t_{1/2}=0.693\min ...(2)$$ For first order reaction $$t_{1/2}=\frac{0.693}{k}$$ Thus, for the reaction $A\to B$ $$t_{1/2}=\frac{0.693}{k}=\frac{0.693}{0.693}=1.0\min$$ Also, for first order reaction, lower the $t_{1/2}$ value, faster is the reaction. $$t_{1/2}\propto \frac{1}{k}$$ and $k$ for $A\to C$ is $\frac{0.693}{0.693}=1{\min }^{-1}$ Thus, reaction (2) is faster than reaction (1) or reaction (1) is slower than reaction (2) Hence, option (b) is the correct answer.