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Saturday, 31 October

JEE Main · Chemistry · The d- and f-Block Elements

Acid-Base Character of Oxides

JEE Main asked Acid-Base Character of Oxides 8 times in 8 of the 108 shifts Lumi analysed, in 2017, 2021, 2024 and 2025. It belongs to d-Block Elements, in The d- and f-Block Elements (Chemistry). The longest wait between two years asking it was 4 years, across 2018 and 2019, which Lumi has no shifts for. In 2021, 2024 and 2025 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
8
in 8 shifts
Years
4 of 8
First asked
2017
last in 2025
Pattern
Frequent
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2017, 2021, 2024 and 2025. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.510.83’170’200.07’210’220’230.09’240.38’250’26

Raw count: 2017: 1 in 1 shift · 2020: 0 in 12 shifts · 2021: 2 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 2 in 18 shifts · 2025: 3 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
  • 20253 of 8
  • 20242 of 18
  • 20230 of 12
  • 20220 of 24
  • 20212 of 24
  • 20200 of 12
  • 20171 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: multi-step.

  • Count acidic oxides plus primary valency
  • Nature of oxide of deduced metal ion

Difficulty

Easy 1Medium 7Hard 0

1 of the 8 questions had a numerical answer.

Every question

All 8 questions

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

  1. 7 Apr 2025, Shift 2 · Q61'X' is the number of acidic oxides among VO2\mathrm{VO_2}, V2O3\mathrm{V_2O_3}, CrO3\mathrm{CrO_3}, V2O5\mathrm{V_2O_5} and Mn2O7\mathrm{Mn_2O_7}.…MediumSingle correct
  2. 7 Apr 2025, Shift 1 · Q61The first transition series metal 'M' has the highest enthalpy of atomisation in its series. One of its aquated ion (Mn+\mathrm{M^{n+}})…MediumSingle correct
  3. 4 Apr 2025, Shift 2 · Q59'X' is the number of electrons in t2g\mathrm{t_{2g}} orbitals of the most stable complex ion among [Fe(NH3)6]3+\mathrm{[Fe(NH_3)_6]^{3+}},…MediumSingle correct
  4. 31 Jan 2024, Shift 2 · Q69Choose the correct statements from the following A. Mn2O7\mathrm{Mn_2O_7} is an oil at room temperature B. V2O4\mathrm{V_2O_4} reacts with acid…MediumOther
  5. 4 Apr 2024, Shift 2 · Q86A first row transition metal with highest enthalpy of atomisation, upon reaction with oxygen at high temperature forms oxides of formula…MediumNumerical value
  6. 24 Feb 2021, Shift 2 · Q38The incorrect\textbf{incorrect} statement among the following is :MediumSingle correct
  7. 27 Aug 2021, Shift 1 · Q40The nature of oxides V2O3\mathrm{V_2O_3} and CrO is indexed as ‘X’ and ‘Y’ type respectively. The correct set of X and Y is :EasySingle correct
  8. 2 Apr 2017 (offline) · Q47In the following reactions, ZnO is respectively acting as a/an : (a) ZnO+Na2O→Na2ZnO2\mathrm{ZnO+Na_2O\rightarrow Na_2ZnO_2} (b)…MediumSingle correct

Shifts: 2 Apr 2017 (offline), 24 Feb 2021, Shift 2, 27 Aug 2021, Shift 1, 31 Jan 2024, Shift 2, 4 Apr 2024, Shift 2, 4 Apr 2025, Shift 2, 7 Apr 2025, Shift 2, 7 Apr 2025, Shift 1.

Same topic

Other ideas in d-Block Elements

d-Block Elements has 31 ideas JEE Main has asked; 21 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas