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Friday, 9 October

NEET UG 2026 · Chemistry · Question 81

NEET 2026 Chemistry, question 81

Question 81 of the NEET 2026 paper (re-exam) is a Chemistry question from Redox Reactions. Its idea, Calculating Oxidation Numbers, was asked 4 times, in 2018, 2020, 2025 and 2026, across NEET 2017–2026. The NTA final answer key gives option 2.

Updated 2026-10-08

Q81 · Chemistry

The correct decreasing order of oxidation state of the underlined atom in each molecule is

  1. 1P‾4O10>S‾O3>H2O‾\mathrm{\underline{P}_4O_{10}>\underline{S}O_3>H_2\underline{O}}
  2. 2N‾2O5>Al‾2O3>H2S‾\mathrm{\underline{N}_2O_5>\underline{Al}_2O_3>H_2\underline{S}}Official answer
  3. 3Pb‾O2>N‾2O3>S‾O3\mathrm{\underline{Pb}O_2>\underline{N}_2O_3>\underline{S}O_3}
  4. 4P‾4O6>Cl‾2O7>Al‾H3\mathrm{\underline{P}_4O_6>\underline{Cl}_2O_7>\underline{Al}H_3}

Official answer: option 2 · NTA final answer key

Same idea

Calculating Oxidation Numbers, in other papers

NEET asked this idea 4 times, in 2018, 2020, 2025 and 2026. The other 3 questions below.

  • 2025 Q55Consider the following compounds : K‾O2\underline{K}O_2, H2O‾2H_2\underline{O}_2 and H2S‾O4H_2\underline{S}O_4 The oxidation states of the…One-line MCQ · Easy
  • 2020 Q125What is the change in oxidation number of carbon in the following reaction ? CH4(g)+4Cl2(g)→CCl4(l)+4HCl(g)\mathrm{CH_4(g) + 4Cl_2(g) \to CCl_4(l) + 4HCl(g)}One-line MCQ · Easy
  • 2018 Q46The correct order of N-compounds in its decreasing order of oxidation states isOne-line MCQ · Easy

Calculating Oxidation Numbers: every question and how it was framed

The chapter

Redox Reactions in ten years of NEET

10 questions from 2017–2026, asked in 8 of 10 papers, about 1.0 a paper. Redox Reactions alone had 10.

Chapter analysisStudy this chapterPractise this chapter

Redox Reactions: questions per paper

0240’172’181’191’201’210’221’231’241’252’26