MCQ on Class 11 Chemistry Chapter 8 Redox Reactions

1 A standard reduction electrode potentials of four metals are A = -0.250 V, B = -0.140 V, C = -0.126 V, D = -0.402 V The metal that displaces A from its aqueous solution is:

A A

B B

C C

D D

View Answer

Answer:D

2 The colourless solution of silver nitrate slowly turns blue on adding copper chips to it because of

A Dissolution of Copper

B Oxidation of Ag+ → Ag

C Reduction of Cu2+ ions

D Oxidation of Cu atoms.

View Answer

Answer:Oxidation of Cu atoms.

3 The oxidation number of Xe in BaXeO6 is

A 8

B 6

C 4

D 10

View Answer

Answer:10

4 Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?

A Copper

B Magnesium

C Iron

D Silver

View Answer

Answer:Magnesium

5 The oxidation process involves

A Increase in oxidation number

B Decrease in oxidation number

C No change in oxidation number

D none of the above

View Answer

Answer:Increase in oxidation number

6 The oxidation number of Mn is maximum in

A MnO₂

B K₂MnO₄

C Mn₃O₄

D KMnO₄.

View Answer

Answer:KMnO₄

7 What is n-factor?

A Equal to product of Number of moles of electrons when Lost or gained by one mole of reductant or oxidant

B When Number of moles of electrons Lost or gained by one mole of reductant or oxidant is not same.

C Equal to Number of moles of electrons Lost or gained by one mole of reductant or oxidant

D None of the above

View Answer

Answer:Equal to Number of moles of electrons Lost or gained by one mole of reductant or oxidant

8 One mole of N₂H₄ loses ten moles of electrons to form a new compound A. Assuming that all the nitrogen appears in the new compound, what is the oxidation state of nitrogen in A? (There is no change in the oxidation state of hydrogen.)

A -1

B -3

C +3

D +5

View Answer

Answer:+3

9 KMnO₄ reacts with oxalic acid according to the equation 2MnO₄^– + 5C₂O₄^2- + 16H+ → 2Mn²⁺ +10CO₂ + 8H₂O Here 20 mL of 0.1 M KMnO₄ is equivalent to

A 50 mL of 0.5 M C₂H₂O₄

B 20 mL of 0.1 M C₂H₂O₄

C 20 mL of 0.5 M C₂H₂O₄

D 50 mL of 0.1 M C₂H₂O₄

View Answer

Answer:50 mL of 0.1 M C₂H₂O₄

10 Which of the following reactions does not involve either oxidation or reduction?

A VO²⁺ → V₂O₃

B Na → Na⁺

C CrO^2-₄ → Cr₂O₂^-7

D Zn²⁺ →Zn

View Answer

Answer:CrO^2-₄ → Cr₂O₂^-7

11 The number of moles of KMnO₄ reduced by one mole of KI in alkaline medium is

A One

B Two

C Five

D One fifth.

View Answer

Answer:Two

12 Which of the following processes does not involve oxidation of iron?

A Formation of Fe(CO)₅ from Fe.

B Liberation of H₂ from steam by iron at high temperature.

C Rusting of iron sheets.

D Decolourisation of blue CuSO₄ solution by iron.

View Answer

Answer:Formation of Fe(CO)₅ from Fe.

13 The oxidation state of Cr in Cr (CO)₆ is

A 0

B 2

C 2

D 6

View Answer

Answer:0

14 How many millilitres of 0.5 M H₂SO₄ are needed to dissolve 0.5 g of copper(II)carbonate?

A 6.01

B 4.5

C 8.1

D 11.1

View Answer

Answer:8.1

15 One mole of N₂H₄ loses ten moles of electrons to form a new compound A. Assuming that all the nitrogen appears in the new compound, what is the oxidation state of nitrogen in A? (There is no change in the oxidation state of hydrogen.

A -1

B -3

C +3

D +5

View Answer