🧪 Chemistry · Chemical Kinetics · NEET & JEE

For a first-order reaction, the half-life t½ in terms of the rate constant k is:

Answer: 0.693/k.

A 0.693/k
B k/0.693
C 0.693 k
D 1/k

Correct answer: A. 0.693/k

Explanation: t½ = 0.693/k for a first-order reaction, independent of the starting concentration.

First-order decay curve: concentration halves every t½, and that half-life is constant - a defining test for first-order kinetics.

Concept context

Study the speed of reactions and what affects it: concentration, temperature, and catalysts. Covers rate law, order of reaction, the Arrhenius equation, and reaction mechanisms step by step.

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For a first-order reaction, the half-life t½ in terms of the rate constant k is:

Concept context

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