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Saturday, 31 October

JEE Main · Chemistry · The Solid State

Empirical Formula from Void Occupancy

JEE Main asked Empirical Formula from Void Occupancy 4 times in 4 of the 108 shifts Lumi analysed, in 2020, 2021 and 2022. It belongs to Crystal Lattices, in The Solid State (Chemistry). The longest wait between two years asking it was 1 year. In 2022 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
4
in 4 shifts
Years
3 of 8
First asked
2020
last in 2022
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2020, 2021 and 2022. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.050.10’170.08’200.03’210.07’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 1 in 24 shifts · 2022: 2 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
  • 20222 of 24
  • 20211 of 24
  • 20201 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Numerical value is the usual form. Skill tested: calculation.

  • Percentage of element from void occupancy
  • Oxidation states from void occupancy in lattice

Difficulty

Easy 1Medium 3Hard 0

3 of the 4 questions had a numerical answer.

Every question

All 4 questions

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

  1. 26 Jun 2022, Shift 2 · Q82In a solid AB, A atoms are in ccp arrangement and B atoms occupy all the octahedral sites. If two atoms from the opposite faces are…MediumNumerical value
  2. 24 Jun 2022, Shift 1 · Q81Atoms of element X form hcp lattice and those of element Y occupy 23\frac{2}{3} of its tetrahedral voids. The percentage of element X in…MediumNumerical value
  3. 31 Aug 2021, Shift 2 · Q52The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites…EasyNumerical value
  4. 6 Sep 2020, Shift 2 · Q41A crystal is made up of metal ions 'M1_1' and 'M2_2' and oxide ions. Oxide ions form a ccp lattice structure. The cation 'M1_1'…MediumSingle correct

Shifts: 6 Sep 2020, Shift 2, 31 Aug 2021, Shift 2, 24 Jun 2022, Shift 1, 26 Jun 2022, Shift 2.

Same topic

Other ideas in Crystal Lattices

Crystal Lattices has 9 ideas JEE Main has asked; 4 of them came up in more than one question.

Topic analysisChapter analysisAll repeated ideas