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Saturday, 31 October

JEE Main · Chemistry · Hydrogen

H-H Bond Dissociation Enthalpy

JEE Main asked H-H Bond Dissociation Enthalpy 3 times in 3 of the 108 shifts Lumi analysed, all in 2021. It belongs to Hydrogen and Hydrides, in Hydrogen (Chemistry). In 2021 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
3
in 3 shifts
Years
1 of 8
First asked
2021
the only year
Pattern
Gone quiet
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.050.10’170’200.10’210’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 3 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20220 of 24
  • 20213 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: recall.

  • Numerical relation between isotope properties
  • Identify incorrect statement about hydrogen

Difficulty

Easy 1Medium 2Hard 0

Every question was multiple choice.

Every question

All 3 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 25 Jul 2021, Shift 1 · Q35At 298.2 K the relationship between enthalpy of bond dissociation (in kJ mol−1^{-1}) for hydrogen (EH\mathrm{E_H}) and its isotope,…MediumSingle correct
  2. 31 Aug 2021, Shift 2 · Q34Which one of the following statements is incorrect ?MediumSingle correct
  3. 4 Aug 2021, Shift 1 · Q37Naturally occurring hydrogen contains three isotopes, protium (H), deuterium (D) and tritium (T). What is correct order of heat of…EasySingle correct

Shifts: 25 Jul 2021, Shift 1, 4 Aug 2021, Shift 1, 31 Aug 2021, Shift 2.

Same topic

Other ideas in Hydrogen and Hydrides

Hydrogen and Hydrides has 29 ideas JEE Main has asked; 21 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisAll repeated ideas