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: A

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: A

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: A

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: A

Question. Acidic medium used in KMnO₄ can be made from which of the following acids?
(a) H₂SO₄
(b) HBr
(c) HCl
(d) HI

Answer: A

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: A

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: A

Question. The average oxidation state of sulphur in Na₂S₄O₆ is
(a) +2.5
(b) +3.0
(c) +2
(d) +3.5

Answer: A

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: A

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: A

Question. In the compounds KMnO₄and K₂Cr₂O₇ the highest oxidation state is of the element
(a) manganese
(b) oxygen
(c) potassium
(d) chromium

Answer: A

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: A

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: A

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: A

Question. Which of the following elements does not show disproportionation tendency?
(a) F
(b) Cl
(c) Br
(d) I

Answer: A

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: A

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: A