CBSE Class 11 Chemistry Redox Reactions MCQs

Question: Which of the following process takes place in oxidation process?

a) Addition of oxygen

b) Addition of hydrogen

c) Addition of chlorine

d) Removal of oxygen

Answer: Addition of oxygen

Question: The loss of electron is termed as

a) oxidation

b) reduction

c) combustion

d) neutralization

Answer: oxidation

Question: When a strip of metallic zinc is placed in an aqueous solution of copper nitrate the blue colour of the solution disappear due to formation of

a) Zn²⁺

b) Cus

c) ZnS

d) Cu²⁺

Answer: Zn²⁺

Question: The correct order of electron releasing tendency of the metals Cu, Zn and Ag is in the order

a) Zn > Cu > Ag

b) Zn > Ag > Cu

c) Cu > Zn > Ag

d) Ag > Zn > Cu

Answer: Zn > Cu > Ag

Question: What is the oxidation number of elements in the free or in the uncombined state ?

a) 0

b) –1

c) +1

d) +2

Answer: 0

Question: ‘Oxidation number of H in NaH, CaH₂ and LiH, respectively is

a) –1,–1, –1

b) –1, +1, + 1

c) +1, +1, –1

d) +1, + 1, + 1

Answer: –1,–1, –1

Question: Which of the following is the correct representative of stock notation for auric chloride?

a) Au(III)Cl₃

b) Au(II)Cl₂

c) Au(I)Cl₂

d) None of these

Answer: Au(III)Cl₃

Question: Oxidation number of N in HNO₃ is

a) + 5

b) + 3.5

c) – 3.5

d) –5

Answer: + 5

Question: The oxidation number of chromium in potassium dichromate is

a) + 6

b) – 5

c) – 2

d) + 2

Answer: + 6

Question: Oxidation number of cobalt in K[Co(CO)₄] is

a) –3

b) +3

c) +1

d) –1

Answer: –3

Question: Oxidation number of carbon in CH₂Cl₂ is

a) 0

b) –4

c) +4

d) –2

Answer: 0

Question: The oxidation state of osmium (Os) in OsO₄ is

a) +8

b) +6

c) +7

d) +4

Answer: +8

Question: Which of the following transition metal has zero oxidation state ?

a) [Fe(CO)₅]

b) NOClO₄

c) NH₂.NH₂

d) CrO₅

Answer: [Fe(CO)₅]

Question: In which of the compounds does 'manganese' exhibit highest oxidation number ?

a) KMnO₄

b) MnO₂

c) Mn₃O₄

d) MnSO₄

Answer: KMnO₄

Question: A metal ion M³⁺ loses 3 electrons, its oxidation number will be

a) +6

b) –3

c) +3

d) 0

Answer: +6

Question: The correct name for NO₂ using stock notation is

a) nitrogen (iv) oxide

b) All of these

c) nitrogen dioxide

d) nitrogen per oxide

Answer: nitrogen (iv) oxide

Question: The oxide, which cannot act as a reducing agent, is

a) CO₂

b) NO₂

c) SO₂

d) ClO₂

Answer: CO₂

Question: The oxidation state of Fe in Fe₃O₄ is

a) 8/3

b) + 2

c) + 3

d) + 6

Answer: 8/3

Question: In oxygen difluoride, the oxidation number of oxygen is

a) + 2

b) – 2

c) – 1

d) +1, – 2

Answer: + 2

Question: Oxygen has an oxidation state of +2 in the compound

a) F₂O

b) None of these

c) CO₂

d) H₂O

Answer: F₂O