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Saturday, 31 October

JEE Main · Chemistry · Chemical Kinetics

First Order Fractional Completion Shortcuts

JEE Main asked First Order Fractional Completion Shortcuts 6 times in 6 of the 108 shifts Lumi analysed, in 2021, 2022 and 2024. It belongs to Integrated Rate Equations, in Chemical Kinetics (Chemistry). The longest wait between two years asking it was 2 years. In 2021, 2022 and 2024 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
6
in 6 shifts
Years
3 of 8
First asked
2021
last in 2024
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021, 2022 and 2024. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.050.10’170’200.07’210.07’220’230.09’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 2 in 24 shifts · 2022: 2 in 24 shifts · 2023: 0 in 12 shifts · 2024: 2 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
  • 20242 of 18
  • 20230 of 12
  • 20222 of 24
  • 20212 of 24
  • 20200 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.

  • Time for fractional completion first order
  • Overall order from time and graph data

Difficulty

Easy 3Medium 3Hard 0

5 of the 6 questions had a numerical answer.

Every question

All 6 questions

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

  1. 8 Apr 2024, Shift 1 · Q85Consider the following reaction A+B→C\mathrm{A + B \rightarrow C} The time taken for A to become 1/4th1/4^{\mathrm{th}} of its initial…MediumNumerical value
  2. 6 Apr 2024, Shift 1 · Q85Time required for 99.9% completion of a first order reaction is __________ times the time required for completion of 90% reaction.(nearest…EasyNumerical value
  3. 28 Jun 2022, Shift 1 · Q88For a first order reaction A →\rightarrow B, the rate constant, k = 5.5×10−145.5 \times 10^{-14} s−1\mathrm{s^{-1}}. The time required for 67%…MediumNumerical value
  4. 24 Jun 2022, Shift 2 · Q65For a first order reaction, the time required for completion of 90% reaction is 'x' times the half life of the reaction. The value of 'x'…EasySingle correct
  5. 18 Mar 2021, Shift 2 · Q57A reaction has a half life of 1 min. The time required for 99.9% completion of the reaction is __________ min. (Round off to the Nearest…EasyNumerical value
  6. 24 Feb 2021, Shift 1 · Q58Gaseous cyclobutene isomerizes to butadiene in a first order process which has a ‘k’ value of 3.3×10−4 s−13.3\times10^{-4}\ \mathrm{s^{-1}}at 153°C.…MediumNumerical value

Shifts: 24 Feb 2021, Shift 1, 18 Mar 2021, Shift 2, 24 Jun 2022, Shift 2, 28 Jun 2022, Shift 1, 6 Apr 2024, Shift 1, 8 Apr 2024, Shift 1.

Same topic

Other ideas in Integrated Rate Equations

Integrated Rate Equations has 15 ideas JEE Main has asked; 9 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas