Redox Reactions PYQs Set 3 (PDF)

Set 3 of 5 · Questions 61-90 of 123

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Mere Teacher · Previous Year Questions NEET Chemistry · Redox Reactions · Set 3 (Q61-90)
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61. $The pair of compounds that can exist together is$ (1) $F e C l_{3}, S n C l_{2}$ (2) $H g C l_{2}, S n C l_{2}$ (3) $F e C l_{2}, S n C l_{2}$ (4) $F e C l_{3}, KI$ 62. $On balancing the given redox reaction, aCr_{2} O_{7}^{(2 -)} + bSO_{3}^{(2 -)} (aq) + cH^{+} (aq) \to 2 aCr^{3 +} (aq) + bSO_{4}^{2 -} (aq) + c /2 H_{2} O (l) the coefficients a, b and c are found to be, respectively:$ (1) $8, 1, 3$ (2) $1, 3, 8$ (3) $3, 8, 1$ (4) $1, 8, 3$ 63. $Thiosulphate reacts differently with iodine and bromine in the reactions given below: 2 S_{2} O_{3}^{2 -} + I_{2} \to S_{4} O_{6}^{2 -} + 2 I^{-} S_{2} O_{3}^{2 -} + 5 Br_{2} + 5 H_{2} O \to 2 SO_{4}^{2 -} + 4 Br^{-} + 10 H^{+} Which of the following statement justifies the above dual behaviour of thiosulphate?$ (1) $Bromine is a stronger oxidant than iodine$ (2) $Thiosulphate undergoes oxidation by bromine and reduction by iodine in these reaction$ (3) $Bromine is a weaker oxidant than iodine$ (4) $Bromine undergoes oxidation and iodine undergoes reduction in these reactions$ 64. $The oxidation states of 'P' in H_{4} P_{2} O_{7}, H_{4} P_{2} O_{5} and, H_{4} P_{2} O_{6}, respectively, are :$ (1) $7,5 and 6$ (2) $5,4 and 3$ (3) $5,3 and 4$ (4) $6,4 and 5$ 65. $In which of the following compounds, an element exhibits two different oxidation states?$ (1) $N_{2} H_{4}$ (2) $NH_{2} CONH_{2}$ (3) $N_{3} H$ (4) $NH_{4} NO_{3}$ 66. $KMnO_{4} oxidises oxalic acid in acidic medium. The number of CO_{2} molecules produced per mole of KMnO_{4} is$ (1) $5$ (2) $4$ (3) $3$ (4) $1.5$ 67. $KMnO_{4} decomposes on heating at 513 K to form O_{2} along with$ (1) $MnO_{2} & K_{2} O_{2}$ (2) $K_{2} MnO_{4} & Mn$ (3) $Mn & KO_{2}$ (4) $K_{2} MnO_{4} & MnO_{2}$ 68. $Identify the values of a, b, c, d and e for the following unbalanced reaction a KNO_{3} + 5 C_{12} H_{22} O_{11} ⟶ b N_{2} + c CO_{2} + dH_{2} O + e K_{2} CO_{3}$ (1) $ab c d e 1012185512$ (2) $ab c d e 6861112$ (3) $ab c d e 48366812$ (4) $ab c d e 4824365524$ 69. $Which of the following options are correct for the reaction? 2[Au(CN)_{2}]^{-} (aq) +Zn(V) \to 2Au(V) + [Zn(CN)_{4}]^{2 -} (aq) (A) Redox reaction (B) Displacement reaction (C) Decomposition reaction (D) Combination reaction Choose the correct answer from the options given below:$ (1) $A only$ (2) $A and D only$ (3) $A and B only$ (4) $C and D only$ 70. $In the conversion of Br_{2} to BrO_{3}^{-}, the oxidation number of Br changes from$ (1) $zero to +5$ (2) $+1 to +5$ (3) $zero to -3$ (4) $+2 to +5$ 71. $At 298 K , the standard electrode potentials of Cu^{2 +} / Cu, Zn^{2 +} / Zn, Fe^{2 +} / Fe and Ag^{+} / Ag are 0.34 V, - 0.76 V, - 0.44 V and 0.80 V , respectively. On the basis of standard electrode potential, predict which of the following reaction can not occur?$ (1) $2 CuSO_{4} (aq) + 2 Ag (s) \to 2 Cu (s) + Ag_{2} SO_{4} (aq)$ (2) $CuSO_{4} (aq) + Zn (s) \to ZnSO_{4} (aq) + Cu (s)$ (3) $CuSO_{4} (aq) + Fe (s) \to FeSO_{4} (aq) + Cu (s)$ (4) $FeSO_{4} (aq) + Zn (s) \to ZnSO_{4} (aq) + Fe (s)$ 72. $Identify the weakest oxidising agent among the following.$ (1) $Li^{+}$ (2) $Na^{+}$ (3) $Cd^{2 +}$ (4) $I_{2}$ 73. $In order to oxidize a mixture of one molecule of each of Fe C_{2} O_{4}, F e_{2} (C_{2} O_{4})_{3}, FeS O_{4} and F e_{2} (S O_{4})_{3} in acidic medium, the number of moles of KMn O_{4} required is:$ (1) $2$ (2) $1$ (3) $3$ (4) $1.5$ 74. $KMnO_{4} oxidises C_{2} H_{2} O_{4} to form CO_{2} . In which of the following, the reaction will be faster?$ (1) $Aq. HCl solution$ (2) $Aq. NaOH solution$ (3) $Aq. NaCl solution$ (4) $Aq. NaHCO_{3} solution$ 75. $Hot concentrated sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions does not show oxidizing behaviour?$ (1) $C u + 2 H_{2} S O_{4} \to C u S O_{4} + S O_{2} + 2 H_{2} O$ (2) $S + 2 H_{2} S O_{4} \to 3 S O_{2} + 2 H_{2} O$ (3) $C + 2 H_{2} S O_{4} \to C O_{2} + 2 S O_{2} + 2 H_{2} O$ (4) $C a F_{2} + H_{2} S O_{4} \to C a S O_{4} + 2 H F$ 76. $The species which does not undergo disproportionation reaction is:$ (1) $ClO_{3}^{-}$ (2) $ClO^{-}$ (3) $ClO_{2}^{-}$ (4) $ClO_{4}^{-}$ 77. $Among P_{4}, S_{8} and N_{2}, the elements which undergo disproportionation when heated with NaOH solution$ (1) $P_{4}, S_{8} only$ (2) $N_{2}, S_{8} only$ (3) $N_{2}, P_{4} only$ (4) $P_{4}, N_{2}, S_{8}$ 78. $The oxidation number of the underlined atom in the following species. Identify the incorrect option.$ (1) $C l O_{3}^{-} is + 5$ (2) $K_{2} C r_{2} O_{7} is + 6$ (3) $H A u C l_{4} is + 3$ (4) $C u_{2} O is - 1$ 79. $In the reaction of oxalate with permanganate in acidic medium, the number of electrons involved in producing one molecule of CO_{2} is:$ (1) $1$ (2) $10$ (3) $2$ (4) $5$ 80. $The correct structure of tribromooctaoxide is$ (1) (2) (3) (4) 81. $Strong reducing and oxidizing agents among the following , respectively, are$ (1) $C e^{3 +} and C e^{4 +}$ (2) $C e^{4 +} an d T b^{4 +}$ (3) $C e^{4 +} an d E u^{2 +}$ (4) $E u^{2 +} and C e^{4 +}$ 82. $Match the following List-I (Type of reaction) (A) Combination Reaction (B) Decomposition Reaction (C) Disproportionation Reaction (D) Displacement Reaction List-II (unbalanced equation) (i) AgNO_{3} + CaCl_{2} \to AgCl + Ca (NO_{3})_{2} (ii) Cl_{2} \to Cl^{-} + ClO_{3}^{-} (iii) Mg + N_{2} \to Mg_{3} N_{2} (IV) KClO_{3} Δ KCl + O_{2} A B C D$ (1) $(iii); (ii); (iv); (i)$ (2) $(i); (iv); (ii); (iii)$ (3) $(i); (ii); (iii); (iv)$ (4) $(iii); (iv); (ii); (i)$ 83. $Which is the best description of the behaviour of bromine in the reaction given below? H_{2} O + B r_{2} \to HOBr + H B r$ (1) $Proton acceptor only$ (2) $Both oxidised and reduced$ (3) $Oxidised only$ (4) $Reduced only$ 84. $S O_{2} C 1_{2} on reaction with excess of water results into acidic mixture S O_{2} C 1_{2} + 2 H_{2} O \to H_{2} S O_{4} + 2HC1 16 moles of NaOH is required for the complete neutralisation of the resultant acidic mixture. The number of moles of S 0_{2} C 1_{2} used is :$ (1) $16$ (2) $8$ (3) $4$ (4) $2$ 85. $What is the number of moles of electrons gained by one mole oxidising agent in following redox reaction? Zn_{(s)} + 2 HCl_{(aq)} ⟶ ZnCl_{2} + H_{2}$ (1) $4$ (2) $3$ (3) $2$ (4) $1$ 86. $When C l_{2} gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from$ (1) $zero to + 1 and zero to - 5$ (2) $zero to - 1 and zero to + 5$ (3) $zero to - 1 and zero to + 3$ (4) $zero to + 1 and zero to - 3$ 87. $What is the oxidation number of S in H_{2} S_{2} O_{8} ?$ (1) $+5$ (2) $+4$ (3) $+7$ (4) $+6$ 88. $The oxidation states of sulphur in the anions S O_{3}^{2 -}, S_{2} O_{4}^{2 -} and S_{2} O_{6}^{2 -} follow the order$ (1) $S_{2} O_{4}^{2 -} < S O_{3}^{2 -} < S_{2} O_{6}^{2 -}$ (2) $S O_{3}^{2 -} < S_{2} O_{4}^{2 -} < S_{2} O_{6}^{2 -}$ (3) $S_{2} O_{4}^{2 -} < S_{2} O_{6}^{2 -} < S O_{3}^{2 -}$ (4) $S_{2} O_{6}^{2 -} < S_{2} O_{4}^{2 -} < S O_{3}^{2 -}$ 89. $(I) H_{2} O_{2} + O_{3} \to H_{2} O + 2 O_{2} (II) H_{2} O_{2} + A g_{2} O \to 2 A g + H_{2} O + O_{2} Role of hydrogen peroxide in the above reactions is respectively$ (1) $oxidizing in (I) and reducing in (II)$ (2) $reducing in (I) and oxidizing in (II)$ (3) $reducing in (I) and (II)$ (4) $oxidizing in (I) and (II)$ 90. $2 I O_{3}^{-} + x I^{-} + 12 H^{+} \to 6 I_{2} + 6 H_{2} O What is the value of x?$ (1) $2$ (2) $12$ (3) $10$ (4) $6$