JEE Main 2019ChemistryChemical KineticsHardMCQ

JEE Main 2019 — Chemical Kinetics Question with Solution

JEE Main 2019 (08 Apr Shift 1)

Question

For the reaction 2A+B→C , the values of initial rate at different reactant concentrations are given in the table below. The rate law for the reactions is:
[A](mol L-1) [B](mol L-1)
Initial Rate
(mol L-1s-1)
0.05 0.05 0.045
0.10 0.05 0.090
0.20 0.10 0.72

Choose an option

Show full solutionCorrect option: D
Correct answer
DRate=k[A][B]2

Step-by-step explanation

From the experiment (1) and (2)
0.050.10x0.050.05y=0.0450.090
12x=12⇒x=1

From the experiment (2) and (3)
0.10.2x0.050.1y=0.090.72
1212y=0.090.72
12y=0.09×20.72
12y=14
y=2
Order of reaction with respect to A is 2 and B=2
∴R∝AB2
Or R=KAB2

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About this question

This is a previous-year question from JEE Main 2019, 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.