AIIMS2018Chemistry-Chemical Kinetics

AIIMS 2018 Chemistry Zero Order Reactions MCQ Question

Type: MCQ-conceptual-Medium-Class 12

Which option is valid for zero order reaction?

A

t1/2=32t1/4t_{1/2} = \frac{3}{2} t_{1/4}

B

t1/2=43t1/4t_{1/2} = \frac{4}{3} t_{1/4}

C

t1/2=2t1/4t_{1/2} = 2 t_{1/4}

D

t1/2=(t1/4)2t_{1/2} = (t_{1/4})^2

Correct Answer

Option C

Detailed Explanation

In a zero-order reaction, the half-life (t₁/₂) is directly proportional to the initial concentration of the reactant, given by the formula t1/2=[A]02kt_{1/2} = \frac{[A]_0}{2k}, where [A]0[A]_0 is the initial concentration and kk is the rate constant. The quarter-life (t₁/₄) can be expressed as t1/4=[A]04kt_{1/4} = \frac{[A]_0}{4k}, leading to the relationship t1/2=2t1/4t_{1/2} = 2 t_{1/4}. Therefore, none of the provided options accurately reflect this relationship, making option C (N/A) the only valid choice, as the other options incorrectly suggest different proportionalities.

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