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Saturday, 31 October

JEE Main · Chemistry · Equilibrium

pH of Polyprotic Acids

JEE Main asked pH of Polyprotic Acids 2 times in 2 of the 108 shifts Lumi analysed, in 2021 and 2026. It belongs to pH and Buffers, in Equilibrium (Chemistry). The longest wait between two years asking it was 5 years.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2021
last in 2026
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

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

00.10.20’170’200.03’210’220’230’240’250.11’26

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

Shift by shift

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

  • 20261 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20220 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

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

  • Species concentration in polyprotic acid
  • Ph of polyprotic acid from ka values

Difficulty

Easy 0Medium 1Hard 1

1 of the 2 questions had a numerical answer.

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. 2 Apr 2026, Shift 2 · Q52The first and second ionization constants of a weak dibasic acid H2A\mathrm{H_2A} are 8.1×10−88.1 \times 10^{-8} and 1.0×10−131.0 \times 10^{-13}…HardSingle correct
  2. 16 Mar 2021, Shift 2 · Q56Sulphurous acid (H2SO3\mathrm{H_2SO_3}) has Ka1=1.7×10−2K_{a_1}=1.7\times10^{-2} and Ka2=6.4×10−8K_{a_2}=6.4\times10^{-8}. The pH of 0.588 M H2SO3\mathrm{H_2SO_3}…MediumNumerical value

Shifts: 16 Mar 2021, Shift 2, 2 Apr 2026, Shift 2.

Same topic

Other ideas in pH and Buffers

pH and Buffers has 22 ideas JEE Main has asked; 11 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas