d- and f-Block Elements PYQs Set 3 (PDF)

Set 3 of 15 · Questions 61-90 of 443

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Mere Teacher · Previous Year Questions JEE Main Chemistry · d- and f-Block Elements · Set 3 (Q61-90)
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61. $context of the lanthanoids, which of the following statement is not correct?$ (1) $There is a gradual decrease in the radii of the members with increasing atomic number in the series.$ (2) $All the member exhibit +3 oxidation state.$ (3) $Because of similar properties the separation of lanthanoids is not easy.$ (4) $Availability of 4f electrons results in the formation of compounds in +4 state for all the members of the series.$ 62. $The number f-electrons in +3 oxidation state of gadolinium (Z = 64) is x and in +2 oxidation state of Ytterbium (Z = 70) is y . The sum of x and y is$ (1) $13$ (2) $20$ (3) $18$ (4) $21$ 63. $The pair of metal ions that can give a spin-only magnetic moment of 3.9 BM for the complex$ (1) $C r^{2 +} and M n^{2 +}$ (2) $V^{2 +} and C o^{2 +}$ (3) $V^{2 +} and F e^{2 +}$ (4) $C o^{2 +} and F e^{2 +}$ 64. $The metal ions that have the calculated spin only magnetic moment value of 4.9 B.M. are : (A) Cr^{2 +} (B) Fe^{2 +} (C) Fe^{3 +} (D) Co^{2 +} (E) Mn^{3 +} Choose the correct answer from the options given below:$ (1) $A, D and E Only$ (2) $A, B and E Only$ (3) $A, C and E Only$ (4) $B and E Only$ 65. $What is the oxidation state of Cr, when the pH of the aqueous solution of potassium dichromate changes from acidic to basic?$ (1) $+5$ (2) $+4$ (3) $+6$ (4) $+3$ 66. $Which from following statements regarding transition elements is not correct?$ (1) $These exhibit properties between ' s' and ' p' block elements.$ (2) $These form cations with incomplete d -subshell.$ (3) $5 d series consists of all elements from lanthanum to mercury of periodic table.$ (4) $These are arranged in four different ' d " series.$ 67. $Which of the following compounds show colour due to d-d transition?$ (1) $CuSO_{4} . 5 H_{2} O$ (2) $K_{2} Cr_{2} O_{7}$ (3) $K_{2} CrO_{4}$ (4) $KMnO_{4}$ 68. $Which of the following shows maximum number of oxidation states?$ (1) $Cr$ (2) $Fe$ (3) $Mn$ (4) $V$ 69. $Which among the following lanthanoids forms most stable +2 oxidation state?$ (1) $Eu (Z = 63)$ (2) $Pm (Z = 61)$ (3) $Ce (Z = 58)$ (4) $Gd (Z = 64)$ 70. $Which of the following ions will exhibit colour in aqueous solutions ?$ (1) $La3+ (Z = 57)$ (2) $Ti3+ (Z = 22)$ (3) $Lu3+ (Z = 71)$ (4) $Sc3+ (Z = 21)$ 71. $What is the number of unpaired electrons present in f -orbital at +3 oxidation state of Lu (Z = 71) ?$ (1) $7$ (2) $2$ (3) $4$ (4) $0$ 72. $Cr^{2 +} and Mn^{3 +} do possess d^{4} electronic configuration. So,$ (1) $Mn^{3 +} is oxidizing agent while Cr^{2 +} is reducing agent$ (2) $Both are reducing agents$ (3) $Mn^{3 +} is reducing agent while Cr^{2 +} is oxidizing agent$ (4) $Both are oxidizing agents$ 73. $Match the following List I (Complex) A. (Ni (en)_{3})^{2 +} B. (Ni (H_{2} O)_{4} (en))^{2 +} C. (Ni (H_{2} O)_{6})^{2 +} D. (Ni (H_{2} O)_{6} (en)_{2})^{2 +} List II (Color) I. Green II. Blue III. Pale blue IV. Violet$ (1) $A-IV, B-I, C-III, D-II$ (2) $A-I, B-II, C-III, D-IV$ (3) $A-IV, B-III, C-I, D-II$ (4) $A-I, B-III, C-II, D-IV$ 74. $More number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is$ (1) $more active nature of the actinoids$ (2) $more energy difference between 5 f and 6 d orbitals than that between 4 f and 5 d orbitals$ (3) $lesser energy difference between 5 f and 6 d orbitals than that between 4 f and 5 d orbitals$ (4) $greater metallic character of the lanthanoids than that of the corresponding actinoids$ 75. $Nitriding is the process of surface hardening of steel by treating it is an atmosphere of$ (1) $N H_{3}$ (2) $O_{3}$ (3) $N_{2}$ (4) $H_{2} S$ 76. $Select the correct order of radii of the given ions$ (1) $Yb^{3 +} < Sm^{3 +} < Dy^{3 +} < Pr^{3 +}$ (2) $Yb^{3 +} < Dy^{3 +} < Sm^{3 +} < Pr^{3 +}$ (3) $Pr^{3 +} < Sm^{3 +} < Dy^{3 +} < Yb^{3 +}$ (4) $Pr^{3 +} < Sm^{3 +} < Yb^{3 +} < Dy^{3 +}$ 77. $Which of the following molecules is colourless?$ (1) $CuSO_{4} \cdot 5 H_{2} O (crystal)$ (2) $CuSO_{4} (anhydrous)$ (3) $(Cu (NH_{3})_{4})^{2 +} (aq)$ (4) $(CuCl_{4})^{2 -} (aq)$ 78. $Given below are two statements: Statement I : The E^{\circ} value of Ce^{4 +} / Ce^{3 +} is + 1.74 V Statement II : Ce is more stable in Ce^{4 +} statethan Ce^{3 +} state. choose the most appropriate answer from the options given below:$ (1) $Both statement I and statement II are correct$ (2) $Statement I is incorrect but statement II iscorrect$ (3) $Both statement I and statement II are incorrect$ (4) $Statement I is correct but statement II isincorrect.$ 79. $Given below are two statements : Statement (I) : Fusion of MnO_{2} with KOH and an oxidising agent gives dark green K_{2} MnO_{4} . Statement (II) : Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion. In the light of the above statements, choose the correct answer from the options given below :$ (1) $Statement I is true but Statement II is false$ (2) $Both Statement I and Statement II are false$ (3) $Statement I is false but Statement II is true$ (4) $Both Statement I and Statement II are true$ 80. $The yellow precipitate formed during the chromyl chloride test is chemically$ (1) $chromic acid$ (2) $lead chromate$ (3) $lead acetate$ (4) $sodium chromate.$ 81. $K_{2} C r_{2} O_{7} on heating with aqueous N a O H gives$ (1) $C r_{2} O_{7}^{2 -}$ (2) $C r (O H)_{2}$ (3) $C r O_{4}^{2 -}$ (4) $C r (O H)_{3}$ 82. $Given below are two statements: Statement I: CrO_{3} is a stronger oxidizing agent than MoO_{3} Statement II: Cr(VI) is more stable than Mo(VI) In the light of the above statements, choose the correct answer from the options given below$ (1) $Statement I is true but Statement II is false$ (2) $Both Statement I and Statement II are true$ (3) $Both Statement I and Statement II are false$ (4) $Statement I is false but Statement II is true$ 83. $An atom has electronic configuration 1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{3} 4 s^{2}, you will place it in$ (1) $fifth group$ (2) $fifteenth group$ (3) $second group$ (4) $third group$ 84. $The stability of Cu^{2 +} is more than Cu^{+} salts in aqueous solutions due to:$ (1) $second ionisation enthalpy$ (2) $first ionisation enthalpy$ (3) $enthalpy of atomisation$ (4) $hydration energy$ 85. $Zn gives H_{2} gas with H_{2} S O_{4} and H C 1 but not with H N O_{3} because$ (1) $Zn act as oxidising agent when react with H N O_{3}$ (2) $H N O_{3} is weaker acid than H_{2} S O_{4} and HC1$ (3) $In electrochemical series Zn is above hydrogen$ (4) $N O_{3}^{-} is reduced in preference to hydronium ion.$ 86. $In +2 oxidation state, which of the following lanthanoids act as reducing agents?$ (1) $Ce, Pr$ (2) $Eu, Gd$ (3) $Eu, Yb$ (4) $Lu, Er$ 87. $Which of the following ions has the maximum magnetic moment?$ (1) $Mn2+$ (2) $Fe2+$ (3) $Ti2+$ (4) $Cr2+.$ 88. $The spin only magnetic moment of Mn^{4 +} ion is nearly$ (1) $3 B.M.$ (2) $6 B.M.$ (3) $4 B.M.$ (4) $5 B.M.$ 89. $What will be the decreasing order of basic strength of the following conjugate bases?^{-} OH, RO, CH_{3} CO O, C I$ (1) $RO >^{-} OH > CH_{3} CO O > CI$ (2) $Cl > RO >^{-} OH > CH_{3} COO O$ (3) $- OH > RO > CH_{3} CO O > C 1$ (4) $CI >^{-} OH > R O > CH_{3} CO O$ 90. $In Chromyl chloride, the oxidation state of chromium is (+)__________.$