JEE Main 2024ChemistryChemical KineticsEasyNumerical

JEE Main 2024 — Chemical Kinetics Question with Solution

JEE Main 2024 (27 Jan Shift 2)

Question

Time required for completion of 99.9% of first order reaction is ________ times of half life (t1/2) of the reaction

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Show full solutionCorrect answer: 10
Correct answer
10

Step-by-step explanation

For first order reaction:
kt=logA0At

A0=Initial concentration of A.

At=Concentration of A at time t.

t99.9%t50%=x=log100100-99.9log10050     =log1000.1log 2     = log 1000log 2    =30.3=10

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About this question

This is a previous-year question from JEE Main 2024, covering the Chemical Kinetics chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.