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Redox Reactions · Question 3

NEET (UG) 2025MCQEasy📈 Topic in 25% papers+4−1
1

Consider the following compounds : KO2, H2 O2 and H2 SO4 The oxidation state of the underlined elements in them are, respectively,

  1. +1, -2, and +4
  2. +4, -4, and +6
  3. +1, -1, and +6
  4. +2, -2, and +6

Answer

(3) +1, -1, and +6

Solution

KO2 (superoxide, O2-): K is an alkali metal, oxidation state = +1.

H2O2 (peroxide): 2(+1) + 2x = 0 x = -1

H2SO4: 2(+1) + x + 4(-2) = 0 x = +6

Answer: (3)

NEET (UG) 2025

Keep practising — Redox Reactions

2

Which reaction is NOT a redox reaction?

  1. Zn + CuSO4 ZnSO4 + Cu
  2. 2KClO3 + I2 2KIO3 + Cl2
  3. H2 + Cl2 2HCl
  4. BaCl2 + Na2SO4 BaSO4 + 2NaCl
NEET (UG) 2024
3

On balancing the given redox reaction, a Cr2O72-(aq) + b SO32-(aq) + cH+(aq) 2a Cr3+(aq) + b SO42-(aq) + c2H2O( ) the coefficients a, b and c are found to be, respectively -

  1. 3, 8, 1
  2. 1, 8, 3
  3. 8, 1, 3
  4. 1, 3, 8
NEET (UG) 2023
4

Which of the following reactions is a decomposition redox reaction?

  1. P4(s) + 3OH-(aq) + 3H2O(l) PH3(g) + 3H2PO2-(aq)
  2. 2Pb(NO3)2(s) 2PbO(s) + 4NO2(g) + O2(g)
  3. N2(g) + O2(g) 2NO(g)
  4. Cl2(g) + 2OH-(aq) ClO-(aq) + Cl-(aq) + H2O(l)
NEET (UG) 2022 (Phase 2)
5

Which of the following reactions is the metal displacement reaction? Choose the right option.

  1. 2Pb(NO3)2 2PbO + 4NO2 + O2
  2. 2KClO3 2KCl + 3O2
  3. Cr2O3 + 2Al Al2O3 + 2Cr
  4. Fe + 2HCl FeCl2 + H2
NEET (UG) 2021
6

What is the change in oxidation number of carbon in the following reaction? CH4(g) + 4Cl2(g) CCl4(l) + 4HCl(g)

  1. 0 to +4
  2. -4 to +4
  3. 0 to -4
  4. +4 to +4
NEET (UG) 2020
7

Which of the following reactions are disproportionation reaction? Select the correct option from the following :

  1. A, C and D
  2. A and B only
  3. A and D only
  4. A, B and C
NEET (UG) 2019
8

Consider the change in oxidation state of bromine corresponding to different emf values as shown in the given diagram : BrO4- 1.82 V BrO3- 1.5 V HBrO 1.595 V Br2 1.0652 V Br- Then the species undergoing disproportionation is :

  1. BrO4-
  2. BrO3-
  3. Br2
  4. HBrO
NEET 2018
9

The correct order of N-compounds in its decreasing order of oxidation states is

  1. HNO3, NO, N2, NH4Cl
  2. HNO3, NO, NH4Cl, N2
  3. HNO3, NH4Cl, NO, N2
  4. NH4Cl, N2, NO, HNO3
NEET 2018
10

For the redox reaction, MnO4- + C2O42- + H+ Mn2+ + CO2 + H2O The correct coefficients of the reactants for the balanced equation are

  1. array|c|c|c| MnO4- & C2O42- & H+ \ 16 & 5 & 2 \ array
  2. array|c|c|c| MnO4- & C2O42- & H+ \ 2 & 5 & 16 \ array
  3. array|c|c|c| MnO4- & C2O42- & H+ \ 2 & 16 & 5 \ array
  4. array|c|c|c| MnO4- & C2O42- & H+ \ 5 & 16 & 2 \ array
NEET 2018
11

Assuming complete ionisation, same moles of which of the following compounds will require the least amount of acidified KMnO4 for complete oxidation?

  1. FeSO3
  2. FeC2O4
  3. Fe(NO2)2
  4. FeSO4
AIPMT 2015

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