🧪 Chemistry · Chemical Kinetics · NEET & JEE

Concentration of A falls from 0.4 M to 0.2 M in 20 min, and from 0.2 M to 0.1 M in another 20 min. The order is:

Answer: First.

A Zero
B First
C Second
D Third

Correct answer: B. First

Explanation: The half-life is constant (20 min) regardless of concentration. This is a hallmark of first-order kinetics.

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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Concentration of A falls from 0.4 M to 0.2 M in 20 min, and from 0.2 M to 0.1 M in another 20 min. The order is:

Concept context

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