Redox Reactions
Practice Questions
MCQ (Single Correct Answer)
1

In the redox reaction between $$\mathrm{Cr}_2 \mathrm{O}_7^{2-} / \mathrm{H}^{+}$$ and sulphite ion, what is the number of moles of electrons involved in producing 3.0 moles of the oxidised product?

COMEDK 2024 Evening Shift
2

In the reaction,

$$2 \mathrm{~S}_2 \mathrm{O}_3^{2-}+\mathrm{I}_2 \rightarrow \mathrm{S}_4 \mathrm{O}_6^{2-}+2 \mathrm{I}^{-}$$

COMEDK 2024 Afternoon Shift
3

When $$3.92 \mathrm{~g}$$ of Mohr salt is dissolved in $$100 \mathrm{~mL}$$ of water, and titrated against $$\mathrm{KMnO}_4$$ solution, $$20 \mathrm{~mL}$$ of this solution required $$18 \mathrm{~mL}$$ of $$\mathrm{KMnO}_4$$ for complete oxidation. The strength of $$\mathrm{KMnO}_4$$ is: [Molar mass of Mohr salt is $$392 \mathrm{~g} \mathrm{~mol}^{-1}$$ and $$\mathrm{KMnO}_4$$ is $$158 \mathrm{~g} \mathrm{~mol}^{-1}$$]

COMEDK 2024 Afternoon Shift
4

Identify the oxidation reaction in which acidified $$\mathrm{KMnO}_4$$ is required

COMEDK 2024 Afternoon Shift
5

An inorganic salt comprises of atoms of elements $$\mathrm{A}, \mathrm{B}$$ and $$\mathrm{C}$$. If the oxidation numbers of A, B and $$\mathrm{C}$$ are $$+3,+6$$ and $$-$$2 respectively, what is the possible formula of the compound?

COMEDK 2024 Morning Shift
6

Choose the group of ions / molecules in which none of the species undergo Disproportionation reaction.

COMEDK 2024 Morning Shift
7

In dilute alkaline solution $$\mathrm{MnO}_4^{-}$$ changes to

COMEDK 2023 Morning Shift
8

In neutral medium $$\mathrm{KMnO}_4$$ oxidises $$\mathrm{MnSO}_4$$ to _________

COMEDK 2023 Evening Shift
9

In the given Redox equation, identify the stoichiometric coefficients $$\mathrm{w}, \mathrm{x}, \mathrm{y}$$ and $$\mathrm{z}$$.

$$\mathrm{ClO}_3^{-1}+\mathrm{w} \mathrm{Cl}^{-1}+\mathrm{xH}^{+} \rightarrow \mathrm{y} \mathrm{H}_2 \mathrm{O}+\mathrm{zCl}_2$$

COMEDK 2023 Evening Shift
10

Identify the catalyst used in the reaction between Iodide and persulphate ions.

$$2 \mathrm{I}^{-}+\mathrm{S}_2 \mathrm{O}_8{ }^{2-} \rightarrow \mathrm{I}_2+2 \mathrm{SO}_4{ }^{2-}$$

COMEDK 2023 Evening Shift
11

KMnO$$_4$$ acts as an oxidising agent in acidic medium. The number of moles of KMnO$$_4$$ that will be required to react with one mole of oxalate ions (to form CO$$_2$$) in acidic solution is

COMEDK 2022
12

Which of the following gas readily de-colourises the acidified KMnO$$_4$$ solution?

COMEDK 2022
13

The oxidation number of Cr in CrO$$_5$$ which has the following structure, is

COMEDK 2021 Chemistry - Redox Reactions Question 15 English

COMEDK 2021
14

For decolourisation of 1 mole of KMnO$$_4$$, the moles of H$$_2$$O$$_2$$ required is

COMEDK 2021
15

In the ionic equation,

$$\mathrm{BiO_3^-+6H^++xe^-\rightarrow Bi^{3+}+3H_2O}$$,

the value of x is

COMEDK 2020
16

Carbon forms two oxides which have different compositions. The equivalent mass of which remains constant?

COMEDK 2020