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Saturday, 31 October

JEE Main · Chemistry · The p-Block Elements

Phosphorus Allotropes

JEE Main asked Phosphorus Allotropes 2 times in 2 of the 108 shifts Lumi analysed, in 2021 and 2022. It belongs to Group 15 & 16, in The p-Block Elements (Chemistry). The longest wait between two years asking it was 1 year.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2021
last in 2022
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

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

00.050.10’170’200.03’210.03’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 1 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
  • 20221 of 24
  • 20211 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.

  • Identify allotropes in conversion sequence
  • Allotrope formed under conditions

Difficulty

Easy 0Medium 2Hard 0

Every question was multiple choice.

Every question

All 2 questions

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

  1. 30 Jun 2022, Shift 1 · Q70A→573 K\mathrm{A}\xrightarrow{573\ \mathrm{K}} Red phosphorus →under pressureheat ; 803 KB\xrightarrow[\text{under pressure}]{\text{heat ; 803 K}} \mathrm{B} Red…MediumSingle correct
  2. 27 Aug 2021, Shift 2 · Q36Which one of the following is formed (mainly) when red phosphorus is heated in a sealed tube at 803 K ?MediumSingle correct

Shifts: 27 Aug 2021, Shift 2, 30 Jun 2022, Shift 1.

Same topic

Other ideas in Group 15 & 16

Group 15 & 16 has 15 ideas JEE Main has asked; 10 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisAll repeated ideas