NCERT Solutions for class 11 Chemistry Chapter 8 Redox Reactions | Redox Reactions MCQs

Questions
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

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.

Answer:Oxidation of Cu atoms.

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3 The oxidation number of Xe in BaXeO6 is
A 8
B 6
C 4
D 10

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

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

Answer:Increase in oxidation number
6 The oxidation number of Mn is maximum in
A MnO2
B K2MnO4
C Mn3O4
D KMnO4.

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

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

Answer:+3
9 KMnO4 reacts with oxalic acid according to the equation 2MnO4– + 5C2O42- + 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

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 CrO2-4 → Cr2O2-7
D Zn2+ →Zn

Answer:CrO2-4 → 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.

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.

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

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

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

Answer:+3
16 Which of the following processes does not involve either oxidation or reduction?
A Formation of slaked lime from quick lime
B Heating Mercuric Oxide
C Formation of Manganese Chloride from Manganese oxide
D Formation of Zinc from Zinc blende

Answer:Formation of slaked lime from quick lime
17 If equal volumes of 1M KMnO4 and 1M K2Cr2O7 solutions are allowed to oxidize Fe2+ in acidic medium. The amount of iron oxidized will be:
A More with KMnO2
B More with K2Cr2O7
C Equal with both oxidising agents
D Cannot be determined

Answer:More with K2Cr2O7
18 The tendency of an electrode to lose electrons is known as
A Electrode Potential
B Reduction Potential
C Oxidation Potential
D E.M.F.

Answer: Oxidation Potential
19 What is known as Autooxidation?
A Formation of H2O by the oxidation of H2O2.
B Formation of H2O2 by the oxidation of H2O.
C Both (1) and (2) are true
D None of the above

Answer:Formation of H2O2 by the oxidation of H2O.
20 The oxidation number of Cl in Cl2O7 is
A + 7
B + 5
C + 3
D – 7

Answer:+ 7

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