Are these the official NEET questions on Redox Reactions?

Yes. They are the questions NTA set in each paper, in its wording. The solutions are written by BrainIt.

Redox Reactions NEET PYQs with Solutions (2020 to 2026) PDF

The questions come from Re-NEET 2026 and NEET 2020. Each shows its answer and solution when you open it, so you can attempt it first. For what the chapter covers and how NEET tests it, see the Redox Reactions guide.

Practise on the CBT screen3 questions, 3 minutes, marked +4 / −1 Download PDF3 pages, 0.7 MB, with answers and solutions

Re-NEET 2026 · the full paper

Re-NEET 2026 · Q57
In an acidic medium, 10 mL of 0.25 M oxalic acid is titrated with $\mathrm{KMnO}_{4}$ solution. If the volume of $\mathrm{KMnO}_{4}$ solution required to reach end point is 10 mL, the strength of the $\mathrm{KMnO}_{4}$ solution is
1. (1)
  0.10 M
2. (2)
  0.20 M
3. (3)
  0.25 M
4. (4)
  0.15 M
Answer and solution
Answer: (1)
Oxalate is oxidised by two electrons ( $\mathrm{C}_{2}\mathrm{O}_{4}^{2-} \rightarrow 2\mathrm{CO}_{2} + 2\mathrm{e}^{-}$ ) so its n-factor is 2, while permanganate in ACIDIC medium is reduced by five electrons ( $\mathrm{MnO}_{4}^{-} \rightarrow \mathrm{Mn}^{2+}$ ) so its n-factor is 5. Equating equivalents, $(0.25 \times 2)(10) = (M \times 5)(10)$ , giving $M = 0.10\ \text{M}$ . NCERT Class 11, Redox Reactions (redox titrations).
Re-NEET 2026 · Q81
The correct decreasing order of oxidation state of the underlined atom in each molecule is
1. (1)
  $\underline{\mathrm{P}}4\mathrm{O}_{10} > \underline{\mathrm{S}}\mathrm{O}_{3} > \mathrm{H}_{2}\underline{\mathrm{O}}$
2. (2)
  $\underline{\mathrm{N}}2\mathrm{O}_{5} > \underline{\mathrm{Al}}2\mathrm{O}_{3} > \mathrm{H}_{2}\underline{\mathrm{S}}$
3. (3)
  $\underline{\mathrm{Pb}}\mathrm{O}_{2} > \underline{\mathrm{N}}2\mathrm{O}_{3} > \underline{\mathrm{S}}\mathrm{O}_{3}$
4. (4)
  $\underline{\mathrm{P}}4\mathrm{O}_{6} > \underline{\mathrm{Cl}}2\mathrm{O}_{7} > \underline{\mathrm{Al}}\mathrm{H}_{3}$
Answer and solution
Answer: (2)
Assigning oxidation numbers in option (2): nitrogen in $\mathrm{N}_{2}\mathrm{O}_{5}$ is +5, aluminium in $\mathrm{Al}_{2}\mathrm{O}_{3}$ is +3, and sulphur in $\mathrm{H}_{2}\mathrm{S}$ is -2 (hydrogen is +1 because sulphur is the more electronegative partner). The sequence +5 > +3 > -2 is genuinely decreasing, so (2) is correct. NCERT Class 11, Redox Reactions (oxidation number rules).

NEET 2020 · the full paper

NEET 2020 · Q131
What is the change in oxidation number of carbon in the reaction CH $_{4}$ (g) + 4Cl $_{2}$ (g) → CCl $_{4}$ (l) + 4HCl(g)?
1. (1)
  0 to +4
2. (2)
  -4 to +4
3. (3)
  0 to -4
4. (4)
  +4 to +4
Answer and solution
Answer: (2)
In $\mathrm{CH}_{4}$ , the oxidation number of carbon is -4 (since hydrogen is +1). In $\mathrm{CCl}_{4}$ , the oxidation number of carbon is +4 (since chlorine is -1). Thus, the change in oxidation number of carbon is from -4 to +4. Chapter: Redox Reactions.

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Redox Reactions: NEET previous year questions

Re-NEET 2026 · the full paper

NEET 2020 · the full paper

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