JEE Chemistry Redox Reactions MCQs Set B

Question: Among NH₃, HNO₃, NaN₃ and Mg₃N₂ the number of molecules having nitrogen in negative oxidation state is

• a) 3
• b) 1
• c) 2
• d) 4

Answer: 3

Question:

• a)

  

   

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: The correct decreasing order of oxidation number of oxygen in compounds BaF₂, O₃, KO₂ and OF₂ is

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) + 5, + 6 and + 6
• b) + 5, + 3 and + 6
• c) + 3, + 6 and + 5
• d) – 3, + 6 and + 6

Answer: + 5, + 6 and + 6

Question: When Cl₂ gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from

• a) zero to –1 and zero to +5
• b) zero to –1 and zero to +3
• c) zero to +1 and zero to –3
• d) zero to +1 and zero to –5

Answer:  zero to –1 and zero to +5

Question: Which of the following arrangements represent increasing oxidation number of the central atom?

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question:  In the reaction shown below, oxidation state of the carbon in reactant and product are (i) and (ii) respectively? Is the given reaction a redox reaction?

• a) (i) 4, (ii) 4, No
• b) (i) 6, (ii) 4, yes
• c) (i) 6, (ii) 6, No
• d) (i) 4, (ii) 4, yes

Answer: (i) 4, (ii) 4, No

Question: What products are expected from the disproportionation reaction of hypochlorous acid?

• a) HCl and HClO₃
• b) HClO₂ and HClO₄
• c) HClO₃ and Cl₂O
• d) HCl and Cl₂O

Answer: HCl and HClO₃

Question:

• a) 16.89
• b) 84.45
• c) 32.22
• d) 28.15

Answer: 16.89

Question:

The value’s of x, y and z in the reaction are, respectively

• a) 2, 5 and 16
• b) 5, 2 and 16
• c) 2, 5 and 8
• d) 5, 2 and 8

Answer: 2, 5 and 16

Question:

• a) 5, 6, 3, 3
• b) 3, 5, 3, 6
• c) 5, 3, 6, 3
• d) 5, 6, 5, 5

Answer: 5, 6, 3, 3

Question: If equal volume of reactants are used, than no. moles of KMnO₄ (moles per liter) used in acidic medium required to completely oxidises the 0.5 M FeSO₃?

• a) 0.3
• b) 0.2
• c) 0.1
• d) 0.4

Answer: 0.3

 More Questions...............................

Question: Acidic medium used in KMnO₄ can be made from which of the following acids?

• a) H₂SO₄
• b) HBr
• c) HCl
• d) HI

Answer: H₂SO₄

Question: If rod of a metal (x) is put in a metal ion solution which is blue in colour , solution turn colorless. The metal rod and solution respectively are?

• a) Both
• b) Aluminium and Cu(II)
• c) Zinc and Cu(II)
• d) None of these

Answer: Both

Question:

• a) All of these
• b) Cl ^–
• c) Br ^–
• d) I ^–

Answer: All of these

Question:

• a) D²⁺/D and C²⁺/C
• b) D²⁺/D and B²⁺/B
• c) B²⁺/B and D²⁺/D
• d) None of these

Answer: D²⁺/D and C²⁺/C

Question:

• a) F₂ and I^–
• b) Cl₂ and Br^–
• c) Br₂ and Cl^–
• d) None of these

Answer: F₂ and I^–

Question: Stronger is oxidising agent, more is

• a) standard reduction potential of that species
• b) the tendency to get it self oxidised
• c) the tendency to lose electrons by that species
• d) standard oxidation potential of that species

Answer: standard reduction potential of that species

Question:

• a) Both
• b)

  A = stronger reducing agent
  B = weaker reducing agent

• c)

  A = weaker oxidising agent
  B = stronger oxidising agent

• d) None of these

Answer: Both

Question: Electrode potential data are given below

• a) Br– < Fe²⁺ < Al
• b) Al < Br– < Fe²⁺
• c) Fe²⁺ < Al < Br–
• d) Al < Fe²⁺ < Br–

Answer: Br– < Fe²⁺ < Al

Question: The average oxidation state of sulphur in Na₂S₄O₆ is

• a) +2.5
• b) +3.0
• c) +2
• d) +3.5

Answer: +2.5

Question: Which of the following species can function both as oxidizing as well as reducing agent ?

• a) ClO^–
• b) Cl^–
• c) ClO₄^–
• d) None of these

Answer: ClO^–

Question: The oxidation number of an element in a compound is evaluated on the basis of certian rules. Which of the following rules is not correct in this respect?

• a) The oxidation number of hydrogen is always + 1.
• b) The algebraic sum of all the oxidation numbers in a compound is zero.
• c) An element in the free or the uncombined state bears oxidation number zero.
• d) In all its compounds, the oxidation number of fluorine is – 1

Answer: The oxidation number of hydrogen is always + 1.

Question:  Nitric oxide acts as a reducing agent in the reaction

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In the compounds KMnO₄and K₂Cr₂O₇ the highest oxidation state is of the element

• a) manganese
• b) oxygen
• c) potassium
• d) chromium

Answer: manganese

Question: Atomic number of an element is 22. The highest O.S. exhibited by it in its compounds is

• a) 4
• b) 2
• c) 1
• d) 3

Answer: 4

Question: Why the displacement reactions of chlorine, bromine and iodine using fluorine are not generally carried out in aqueous solution?

• a) Fluorine being very reactive attacks water and displaces oxygen of water
• b) chlorine, bromine and iodine reacts with water and displace oxygen of water
• c) Fluorine does not react with chlorine, bromine and iodine in aqueous media
• d) None of these

Answer: Fluorine being very reactive attacks water and displaces oxygen of water

Question: Which of the following statement is not true ?

• a) F₂, Cl₂, Br₂ and I₂ can be recovered by halogen displacement reactions by using their respective halides
• b) Displacement reaction of chlorine with Br^– and I^– form the basis of identifying Br^– and I^– in laboratory using layer test
• c) F₂ can be recovered from F^– by oxidising it electrolytically
• d) None of these

Answer: F₂, Cl₂, Br₂ and I₂ can be recovered by halogen displacement reactions by using their respective halides

Question: Which of the following do not show disproportionation reaction?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The following species will not exhibit disproportionation reaction

• a)

  

• b) None of these
• c)

  

• d)

  

Answer:

Question:

• a) Bromine is both reduced and oxidised
• b) Bromine is neither reduced nor oxidised
• c) Bromine is reduced and water is oxidised
• d) Bromine is oxidised and carbonate is reduced

Answer: Bromine is both reduced and oxidised

Question:  Which one of the following reactions involves disproportionation?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following elements does not show disproportionation tendency?

• a) F
• b) Cl
• c) Br
• d) I

Answer: F

Question: Phosphorus, sulphur and chlorine undergo disproportion in the ...A... medium. Here, A refers to

• a) alkaline
• b) acidic
• c) neutral
• d) None of these

Answer: alkaline

Question:

• a) decomposition reaction
• b) None of these
• c) addition reaction
• d) displacement reaction

Answer: decomposition reaction

Question: How will you balance the total ionic charge of reactant and products if reaction is carried out in acidic solution?

• a) By using H⁺ ions
• b) By using OH^– ions
• c) Adding H₂O molecules to the reactant or product
• d) Multiplying by suitable coefficients

Answer: By using H⁺ ions

Question:

• a) Both
• b) By adding 2 OH^– ions on right side
• c) By adding one H²O molecule to left side
• d) None of these

Answer: Both

Question:

• a) 2, 1, 1
• b) 2, 2, 2
• c) 2, 2, 1
• d) 4, 4, 2

Answer: 2, 1, 1

Question:

• a) 2 : 3
• b) 1 : 3
• c) 1 : 1
• d) 3 : 2

Answer: 2 : 3

Question:

• a) Mn⁺²
• b) Mn⁺⁴
• c) MnO₂
• d) Mn

Answer:  Mn⁺²

Question:

• a) x = 8, y = 3
• b) x = 3, y = 8
• c) x = 4, y = 6
• d) x = 8, y = 6

Answer: x = 8, y = 3

Question:

• a) Sn⁴⁺ (aq)
• b) Sn
• c) Sn³⁺ (aq)
• d) Sn²⁺ (aq)

Answer:  Sn⁴⁺ (aq)

Question:

• a) 3, 1, 6
• b) 2, 1, 2
• c) 2, 1, 3
• d) 3, 1, 4

Answer: 3, 1, 6

Question: The values of x and y in the following redox reaction

• a) 3, 1, 6
• b) 2, 1, 2
• c) 2, 1, 3
• d) 3, 1, 4

Answer: 3, 1, 6

Question:

• a) x = 3, y = 5
• b) x = 5, y = 3
• c) x = 2, y = 4
• d) x = 4, y = 2

Answer: x = 3, y = 5