JEE Chemistry Redox Reactions MCQs Set A

Question. Which of the following process takes place in oxidation process?
(a) Addition of oxygen
(b) Removal of oxygen
(c) Addition of hydrogen
(d) Addition of chlorine

Answer: A

Question. The loss of electron is termed as
(a) oxidation
(b) combustion
(c) neutralization
(d) reduction

Answer: A

Question. One mole of N₂H₄ loses 10 moles of electrons to form a new compound, y. Assuming that all nitrogen appear in the new compound, what is the oxidation state of nitrogen in y (There is no change in the oxidation state of hydrogen )
(a) +3
(b) –1
(c) –3
(d) +5

Answer: A

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) Cu²⁺
(d) ZnS

Answer: A

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: A

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: A

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: A

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: A

Question. Oxidation number of N in HNO₃ is
(a) + 5
(b) + 3.5
(c) – 3.5
(d) –5

Answer: A

Question. The oxidation number of chromium in potassium dichromate is
(a) + 6
(b) – 2
(c) – 5
(d) + 2

Answer: A

Question. The oxidation number of sulphur in S₈, S₂F₂, H₂S respectively, are
(a) 0, +1 and –2
(b) 0, +1 and +2
(c) +2, +1 and –2
(d) –2, +1 and –2

Answer: A

Question. Oxidation number of cobalt in K[Co(CO)₄] is
(a) –1
(b) –3
(c) +3
(d) +1

Answer: A

Question. Oxidation number of nitrogen in (NH₄)₂SO₄ is
(a) –3
(b) –1
(c) –1/3
(d) +1

Answer: A

Question. Oxidation number of carbon in CH₂Cl₂ is
(a) 0
(b) –4
(c) +4
(d) –2

Answer: A

Question. The oxidation state of osmium (Os) in OsO₄ is
(a) +8
(b) +6
(c) +7
(d) +4

Answer: A

Question. In which of the compounds does 'manganese' exhibit highest oxidation number ?
(a) NOClO₄
(b) NH₂.NH₂
(c) CrO₅
(d) None of these

Answer: A

Question. In which of the compounds does 'manganese' exhibit highest oxidation number ?
(a) K₂MnO₄
(b) MnSO₄
(c) Mn₃O₄
(d) MnO₂

Answer: A

Question. In which of the following compounds the oxidation number of carbon is not zero?
(a) CH₃CHO
(b) CH₃COOH
(c) HCHO
(d) C₁₂H₂₂O₁₁

Answer: A

Question.  A metal ion M³⁺ loses 3 electrons, its oxidation number will be
(a) +6
(b) –3
(c) +3
(d) 0

Answer: A

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: A

Question. The oxide, which cannot act as a reducing agent, is
(a) CO₂
(b) NO₂
(c) SO₂
(d) ClO₂

Answer: A

Question. The oxidation state of Fe in Fe₃O₄ is
(a) 8/3
(b) + 2
(c) + 3
(d) + 6

Answer: A

Question. In oxygen difluoride, the oxidation number of oxygen is
(a) + 2
(b) – 2
(c) – 1
(d) +1, – 2

Answer: A

Question. Oxygen has an oxidation state of +2 in the compound
(a) F₂O
(b) CO₂
(c) H₂O₂
(d) H₂O

Answer: A

Question.  The number of electrons involved in the reduction of one nitrate ion to hydrazine is
(a) 7
(b) 5
(c) 8
(d) 3

Answer: A

Question. Arrange the following in the order of their decreasing electrode potentials : Mg, K, Ba and Ca
(a) Ca, Mg, K, Ba
(b) K, Ca, Ba, Mg
(c) Ba, Ca, K, Mg
(d) Mg, Ca, Ba, K

Answer: A

Question. The standard electrode potentials of four elements A, B, C and D are –3.05, –1.66, –0.40 and +0.80. The highest chemical reactivity will be exhibited by
(a) A
(b) C
(c) B
(d) D

Answer: A

Question. Which of the following sequences of T and F is correct for given statements. Here T stands for true and F stands for false statements
(i) Reducing agents lower the oxidation number of an element in a given substance. These reagents are also called as reductants
(ii) Reducing agents are acceptor of electrons
(iii) Loss of electron(s) by any species is called oxidation reaction
(iv) Oxidation and reduction always occur simultaneously.
(a) TFTT
(b) FTTT
(c) TTTT
(d) TFFT

Answer: A

Question.  If aqueous solution of H₂O₂ is made acidic. For this which of the following statement(s) is/are correct ?
(i) This aqueous solution oxidizes I^–
(ii) This aqueous solution oxidizes F^–
(a) Statement (i) is correct and (ii) is incorrect
(b) Statement (ii) is correct and (i) is incorrect
(c) Both statements (i) and (ii) are incorrect
(d) Both statements (i) and (ii) are correct

Answer: A

Question.  Which of the following statement(s) is/are correct ?
(i) All alkali metals and some alkaline earth metals (Ca, Sr and Ba) displace hydrogen from cold water.
(ii) Magnesium and iron react with steam as well as acids to produce hydrogen gas.
(iii) Cadmium and tin do not react with steam but displace hydrogen from acids.
(a) (i), (ii) and (iii)
(b) (ii) only
(c) (i) and (ii)
(d) (i) and (iii)

Answer: A

Question. Which of the following statement(s) is/are correct ?
(i) Oxidation state of carbon in C₃H₄ is –(4/3).
(ii) Electrons are never shared in fraction.
(a) (i) and (ii)
(b) Only (i)
(c) Neither (i) nor (ii)
(d) Only (ii)

Answer: A