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NEET UG 2020 · Chemistry · Question 125

NEET 2020 Chemistry, question 125

Question 125 of the NEET 2020 paper (code E1) 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 3.

Updated 2026-10-08

Q125 · Chemistry

What 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)}

  1. 1+4 to +4
  2. 20 to +4
  3. 3−4-4 to +4Official answer
  4. 40 to −4-4

Official answer: option 3 · 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.

  • 2026 Q81The correct decreasing order of oxidation state of the underlined atom in each molecule isOne-line MCQ · Medium
  • 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
  • 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