Easy INTEGER +4 / -1 PYQ · JEE Mains 2022

$$\matrix{ {[A]} & \to & {[B]} \cr {{\mathop{\rm Reactant}\nolimits} } & {} & {{\mathop{\rm Product}\nolimits} } \cr } $$

If formation of compound $[\mathrm{B}]$ follows the first order of kinetics and after 70 minutes the concentration of $[\mathrm{A}]$ was found to be half of its initial concentration. Then the rate constant of the reaction is $x \times 10^{-6} \mathrm{~s}^{-1}$. The value of $x$ is ______________. (Nearest Integer)

Answer (integer) 165

Solution

$\mathrm{K}=\frac{0.693}{\mathrm{t}_{1 / 2}}=\frac{0.693}{70 \times 60}$<br/><br/> $=\frac{6930}{7 \times 6} \times 10^{-6}$<br/><br/> $=165 \times 10^{-6} \mathrm{~s}^{-1}$

About this question

Subject: Chemistry · Chapter: Chemical Kinetics · Topic: Rate of Reaction

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