Redox Reactions PYQs Set 4 (PDF)

Set 4 of 6 · Questions 91-120 of 163

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Redox Reactions · Set 4 (Q91-120)
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91. $KMnO_{4} oxidises oxalic acid in acidic medium. The number of CO_{2} molecules produced per mole of KMnO_{4} is$ (1) $5$ (2) $4$ (3) $3$ (4) $1.5$ 92. $KMnO_{4} decomposes on heating at 513 K to form O_{2} along with$ (1) $MnO_{2} & K_{2} O_{2}$ (2) $K_{2} MnO_{4} & Mn$ (3) $Mn & KO_{2}$ (4) $K_{2} MnO_{4} & MnO_{2}$ 93. $Identify the values of a, b, c, d and e for the following unbalanced reaction a KNO_{3} + 5 C_{12} H_{22} O_{11} ⟶ b N_{2} + c CO_{2} + dH_{2} O + e K_{2} CO_{3}$ (1) $ab c d e 1012185512$ (2) $ab c d e 6861112$ (3) $ab c d e 48366812$ (4) $ab c d e 4824365524$ 94. $Which of the following options are correct for the reaction? 2[Au(CN)_{2}]^{-} (aq) +Zn(V) \to 2Au(V) + [Zn(CN)_{4}]^{2 -} (aq) (A) Redox reaction (B) Displacement reaction (C) Decomposition reaction (D) Combination reaction Choose the correct answer from the options given below:$ (1) $A only$ (2) $A and D only$ (3) $A and B only$ (4) $C and D only$ 95. $In the conversion of Br_{2} to BrO_{3}^{-}, the oxidation number of Br changes from$ (1) $zero to +5$ (2) $+1 to +5$ (3) $zero to -3$ (4) $+2 to +5$ 96. $At 298 K , the standard electrode potentials of Cu^{2 +} / Cu, Zn^{2 +} / Zn, Fe^{2 +} / Fe and Ag^{+} / Ag are 0.34 V, - 0.76 V, - 0.44 V and 0.80 V , respectively. On the basis of standard electrode potential, predict which of the following reaction can not occur?$ (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) $FeSO_{4} (aq) + Zn (s) \to ZnSO_{4} (aq) + Fe (s)$ 97. $Identify the weakest oxidising agent among the following.$ (1) $Li^{+}$ (2) $Na^{+}$ (3) $Cd^{2 +}$ (4) $I_{2}$ 98. $In order to oxidize a mixture of one molecule of each of Fe C_{2} O_{4}, F e_{2} (C_{2} O_{4})_{3}, FeS O_{4} and F e_{2} (S O_{4})_{3} in acidic medium, the number of moles of KMn O_{4} required is:$ (1) $2$ (2) $1$ (3) $3$ (4) $1.5$ 99. $KMnO_{4} oxidises C_{2} H_{2} O_{4} to form CO_{2} . In which of the following, the reaction will be faster?$ (1) $Aq. HCl solution$ (2) $Aq. NaOH solution$ (3) $Aq. NaCl solution$ (4) $Aq. NaHCO_{3} solution$ 100. $Hot concentrated sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions does not show oxidizing behaviour?$ (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) $C a F_{2} + H_{2} S O_{4} \to C a S O_{4} + 2 H F$ 101. $The species which does not undergo disproportionation reaction is:$ (1) $ClO_{3}^{-}$ (2) $ClO^{-}$ (3) $ClO_{2}^{-}$ (4) $ClO_{4}^{-}$ 102. $Among P_{4}, S_{8} and N_{2}, the elements which undergo disproportionation when heated with NaOH solution$ (1) $P_{4}, S_{8} only$ (2) $N_{2}, S_{8} only$ (3) $N_{2}, P_{4} only$ (4) $P_{4}, N_{2}, S_{8}$ 103. $The oxidation number of the underlined atom in the following species. Identify the incorrect option.$ (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) $C u_{2} O is - 1$ 104. $In the reaction of oxalate with permanganate in acidic medium, the number of electrons involved in producing one molecule of CO_{2} is:$ (1) $1$ (2) $10$ (3) $2$ (4) $5$ 105. $The correct structure of tribromooctaoxide is$ (1) (2) (3) (4) 106. $Strong reducing and oxidizing agents among the following , respectively, are$ (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) $E u^{2 +} and C e^{4 +}$ 107. $Match the following List-I (Type of reaction) (A) Combination Reaction (B) Decomposition Reaction (C) Disproportionation Reaction (D) Displacement Reaction List-II (unbalanced equation) (i) AgNO_{3} + CaCl_{2} \to AgCl + Ca (NO_{3})_{2} (ii) Cl_{2} \to Cl^{-} + ClO_{3}^{-} (iii) Mg + N_{2} \to Mg_{3} N_{2} (IV) KClO_{3} Δ KCl + O_{2} A B C D$ (1) $(iii); (ii); (iv); (i)$ (2) $(i); (iv); (ii); (iii)$ (3) $(i); (ii); (iii); (iv)$ (4) $(iii); (iv); (ii); (i)$ 108. $Which is the best description of the behaviour of bromine in the reaction given below? H_{2} O + B r_{2} \to HOBr + H B r$ (1) $Proton acceptor only$ (2) $Both oxidised and reduced$ (3) $Oxidised only$ (4) $Reduced only$ 109. $S O_{2} C 1_{2} on reaction with excess of water results into acidic mixture S O_{2} C 1_{2} + 2 H_{2} O \to H_{2} S O_{4} + 2HC1 16 moles of NaOH is required for the complete neutralisation of the resultant acidic mixture. The number of moles of S 0_{2} C 1_{2} used is :$ (1) $16$ (2) $8$ (3) $4$ (4) $2$ 110. $What is the number of moles of electrons gained by one mole oxidising agent in following redox reaction? Zn_{(s)} + 2 HCl_{(aq)} ⟶ ZnCl_{2} + H_{2}$ (1) $4$ (2) $3$ (3) $2$ (4) $1$ 111. $When C l_{2} gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from$ (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) $zero to + 1 and zero to - 3$ 112. $What is the oxidation number of S in H_{2} S_{2} O_{8} ?$ (1) $+5$ (2) $+4$ (3) $+7$ (4) $+6$ 113. $The oxidation states of sulphur in the anions S O_{3}^{2 -}, S_{2} O_{4}^{2 -} and S_{2} O_{6}^{2 -} follow the order$ (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) $S_{2} O_{6}^{2 -} < S_{2} O_{4}^{2 -} < S O_{3}^{2 -}$ 114. $The volume of HC1, containing 73 g L^{- 1} required to completely neutralise NaOH obtained by reacting 0.69 g of metallic sodium with water, is _______mL. (Nearest Integer)(Given : molar Masses of N a_{?} Cl, O, H are 23, 35.5. 16 and 1 e m o l^{- 1} respectively)$ 115. $The total change in the oxidation state of manganese involved in the reaction of K M n O_{4} and potassium iodide in the acidic medium is________.$ 116. $When 10mL of an aqueous solution of F e^{2 +} ions was titrated in the presence of dil H_{2} S O_{4} using diphenylamine indicator, 15mL of 0.02M solution of K_{2} C r_{2} O_{7} was required to get the end point. The molarity of the solution containing F e^{2 +} ions is x \times 1 0^{- 2} M . The value of x is (Nearest integer)$ 117. $2 MnO_{4}^{-} + bC_{2} O_{4}^{2 -} + cH^{+} \to xMn^{2 +} + yCO_{2} + zH_{2} O If the above equation is balanced with integer coefficients, the value of c is (Round off to the Nearest Integer)$ 118. $The neutralization occurs when 10 mL of 0.1 M acid 'A' is allowed to react with 30 mL of 0.05 M base M (O H)_{2} . The basicity of the acid 'A' is______. [M is a metal]$ 119. $5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0.1 M solution ?Given : Molar Mass of Na, O and H is 23, 16 and 1 g m o l^{- 1} respectively$ 120. $20 mL of 0.02 M hypo solution is used for the titration of 10 mL of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of C u^{2 +} is found to be _____x 1 0^{- 2} M [nearest integer]Given : 2 C u^{2 +} + 4 I^{-} \to C u_{2} I_{2} + I_{2} I_{2} + 2 S_{2} O_{3}^{2 -} \to 2 I^{-} + S_{4} O_{6}^{2 -}$