JEE Main 2023ChemistryHydrogenPreparation And Properties Of HydrogeneasyMCQ

JEE Main 2023 — Hydrogen Question with Solution

From: JEE Main 2023 (Online) 13th April Evening Shift

Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Isotopes of hydrogen have almost same chemical properties, but difference in their rates of reaction.

Reason R : Isotopes of hydrogen have different enthalpy of bond dissociation.

In the light of the above statements, choose the most appropriate answer from the options given below:

Choose an option

Show full solutionCorrect option: D
Correct answer
DBoth A and R are correct and R is the correct explanation of A

Step-by-step explanation

Assertion A : Isotopes of hydrogen (protium, deuterium, and tritium) have almost the same chemical properties because they have the same number of protons and electrons, which dictate chemical behavior. However, they differ in their rates of reaction due to differences in their atomic masses, which affect reaction kinetics.

Reason R : The isotopes of hydrogen have different enthalpy of bond dissociation due to their differences in atomic mass. The stronger bond in deuterium compared to protium, for example, leads to higher bond dissociation enthalpy. This, in turn, influences the rate of reactions involving these isotopes, as breaking the bonds requires different amounts of energy.

Therefore, the correct answer is Both A and R are correct, and R is the correct explanation of A.

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About this question

This is a previous-year question from JEE Main 2023, covering the Hydrogen 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.