d- and f-Block Elements PYQs Set 4 (PDF)

Set 4 of 14 · Questions 91-120 of 399

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Mere Teacher · Previous Year Questions NEET Chemistry · d- and f-Block Elements · Set 4 (Q91-120)
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91. $Alkaline oxidative fusion of MnO_{2} gives "A" which on electrolytic oxidation in alkaline solution produces B . A and B respectively are:$ (1) $Mn_{2} O_{7} and MnO_{4}^{-}$ (2) $MnO_{4}^{2 -} and MnO_{4}^{-}$ (3) $Mn_{2} O_{3} and MnO_{4}^{2 -}$ (4) $MnO_{4}^{2 -} and Mn_{2} O_{7}$ 92. $Assertion (A) : Transition metals and their complexes show catalytic activity.Reason (R) : The activation energy of a reaction is lowered by the catalyst.$ (1) $Both (A) and (R) are correct and (R) is the correct explanation of (A) .$ (2) $Both (A) and (R) are correct but (R) is not the correct explanation of (A).$ (3) $(A) is correct but (R) is incorrect.$ (4) $(A) is incorrect but (R) is correct.$ 93. $In context with the transition elements, which of the following statements is incorrect ?$ (1) $In the highest oxidation states, the transition metal show basic character and form cationic complexes.$ (2) $In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding.$ (3) $Once the d5 configuration is exceeded, the tendency to involve all the 3d electrons in bonding decreases.$ (4) $In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes.$ 94. $KMnO_{4} acts as an oxidising agent in alkaline medium. When alkaline KMnO_{4} is treated with KI, iodide ion is oxidised to$ (1) $I_{2}$ (2) $IO^{-}$ (3) $IO_{3}^{-}$ (4) $IO_{4}^{-}$ 95. $Match List-I with List-II List-I Species (A) Cr^{+ 2} (B) Mn^{+} (C) Ni^{+ 2} (D) V^{+} List-II Electronic distribution (I) 3 d^{8} (II) 3 d^{3} 4 s^{1} (III) 3 d^{4} (IV) 3 d^{5} 4 s^{1} Choose the correct answer from the options given below:$ (1) $(A)-I, (B)-II, (C)-III, (D)-IV$ (2) $(A)-III, (B) - IV, (C) - I, (D)-II$ (3) $(A)-IV, (B)-III, (C)-I, (D)-II$ (4) $(A)-II, (B)-I, (C)-IV, (D)-III$ 96. $Identify correct statements from below: A. The chromate ion is square planar. B. Dichromates are generally prepared from chromates. C. The green manganate ion is diamagnetic. D. Dark green coloured K_{2} MnO_{4} disproportionates in a neutral or acidic medium to give permanganate. E. With increasing oxidation number of transition metal, ionic character of the oxides decreases. Choose the correct answer from the options given below:$ (1) $B, C, D only$ (2) $A, D, E only$ (3) $A, B, C only$ (4) $B, D, E only$ 97. $Correct order of basic strength of metallic hydroxides$ (1) $Ce (OH)_{3} < Lu (OH)_{3} < Eu (OH)_{3}$ (2) $Ce (OH)_{3} < Eu (OH)_{3} < Lu (OH)_{3}$ (3) $Lu (OH)_{3} < Eu (OH)_{3} < Ce (OH)_{3}$ (4) $Lu (OH)_{3} < Ce (OH)_{3} < Eu (OH)_{3}$ 98. $A ⟶ 4 KOH, O_{2} 2 B (Green) + 2 H_{2} O B ⟶ 4 HCl 2 C (Purple) + MnO_{2} + 2 H_{2} O 2 C ⟶ H_{2} O, KI 2 A + KOH + D In the above sequence of reactions, A and D, respectively, are:$ (1) $KI and KMnO_{4}$ (2) $MnO_{2} and KIO_{3}$ (3) $KIO_{3} and MnO_{2}$ (4) $KI and K_{2} MnO_{4}$ 99. $Which of the following pairs has the same size?$ (1) $F e^{2 +}, N i^{2 +}$ (2) $Z r^{4 +}, T i^{4 +}$ (3) $Z r^{4 +}, H f^{4 +}$ (4) $Z n^{2 +}, H f^{4 +}$ 100. $Which of the following statements is incorrect for pair of elements Zr - Hf ?$ (1) $Both possess same number of valence electrons.$ (2) $Both have identical atomic sizes.$ (3) $Both have almost identical ionic radii.$ (4) $Both of these belong to same period of periodic table.$ 101. $Assuming complete ionisation, same moles of which of the following compounds will require the least amount of acidified K M n O_{4} for complete oxidation?$ (1) $F e S O_{3}$ (2) $F e C_{2} O_{4}$ (3) $F e (N O_{2})_{2}$ (4) $F e S O_{4}$ 102. $Choose the incorrect statement among the following -$ (1) $The chemistry of different lanthanoids is very similar$ (2) $4 f and 5 f-orbitals are equally shielded$ (3) $d-block element show irregular and erratic chemical properties among themselves$ (4) $La and Lu have partially filled d-orbitals and no other partially filled orbitals$ 103. $Identify the correct statements from the following: I. The ionic radius of Pr^{3 +}, Dy^{3 +} and Sm^{3 +} follow the order, Sm^{3 +} > Pr^{3 +} > Dy^{3 +} . II. Eu^{2 +} acts as strong reducing reagent. III. Pu exhibits +7 oxidation state.$ (1) $I, II only$ (2) $I, III only$ (3) $I, II, III$ (4) $II, III only$ 104. $electronic configuration of Cu (II) is 3 d^{9} whereas that of Cu (I) is 3 d^{10} . Which of the following is correct?$ (1) $Stability of Cu (I) and Cu (II) depends on nature of copper salts$ (2) $Cu (II) is more stable$ (3) $Cu (I) and Cu (II) are equally stable$ (4) $Cu (II) is less stable$ 105. $When M n O_{2} is fused with KOH, a coloured compound is formed. The product and its colour is :$ (1) $K_{2} M n O_{4}, green$ (2) $M n_{2} O_{3}, brown$ (3) $M n_{2} O_{4}, black$ (4) $K M n O_{4}, purple$ 106. $The incorrect statement in respect of chromyl chloride test is$ (1) $formation of lead chromate$ (2) $formation of chromyl chloride$ (3) $liberation of chlorine$ (4) $formation of red vapours.$ 107. $Identify the element having highest ionization enthalpy.$ (1) $Ti$ (2) $Sc$ (3) $Zn$ (4) $Ni$ 108. $Lanthanide contraction is due to increase in$ (1) $shielding by 4 f electrons$ (2) $atomic number$ (3) $effective nuclear charge$ (4) $size of 4 f -orbital.$ 109. $The metal that shows highest and maximum number of oxidation state is :$ (1) $Fe$ (2) $Mn$ (3) $Co$ (4) $Ti$ 110. $Observe the following ions V^{2 +}, Zn^{2 +}, Cu^{2 +}, Fe^{2 +}, Fe^{3 +}, Ti^{3 +}, Sc^{3 +}, Ti^{4 +}, Ni^{3 +}, Co^{3 +}, Cu^{+} How many ions in the above list have zero magnetic moment?$ (1) $4$ (2) $3$ (3) $5$ (4) $2$ 111. $The element with highest standard reduction potential (in volt) (M^{2 +} \to M) among the first row of transition elements is$ (1) $Ti$ (2) $Ni$ (3) $Cr$ (4) $Cu$ 112. $Given below are some of the statements about Mn and Mn2O7. Identify the correct statements.(A) Mn forms the oxide Mn2O7, in which Mn is in its highest oxidation state.(B) Oxygen stabilizes the Mn in higher oxidation states by forming multiple bonds with Mn .(C) Mn2O7 is an ionic oxide.(D) The structure of Mn2O7 consists of one bridged oxygen. Choose the correct answer from the options given below :$ (1) $(A) (B) and (D) Only$ (2) $(A) (B) and (C) Only$ (3) $(A) (B) (C) and (D)$ (4) $(A) (C) and (D) Only$ 113. $Given below are two statements : Statement I: The first ionization enthalpy of Cr is lower than that of Mn . Statement II: The second and third ionization enthalpies of Cr are higher than those of Mn . In the light of the above statements, choose the correct answer from the options given below:$ (1) $Both Statement I and Statement II are true$ (2) $Both Statement I and Statement II are false$ (3) $Statement I is false but Statement II is true$ (4) $Statement I is true but Statement II is false$ 114. $Which of the following is an amphoteric oxide ?$ (1) $CrO3$ (2) $Cr2O3$ (3) $V2O3$ (4) $TiO$ 115. $For the four successive transion elements (Cr, Mn, Fe and Co), the stability of +2 oxidation state will be there in which of the following order ? (At. nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)$ (1) $Mn > Fe > Cr > Co$ (2) $Fe > Mn > Co > Cr$ (3) $Co > Mn > Fe > Cr$ (4) $Cr > Mn > Co > Fe$ 116. $Assertion (A) : Transition elements have higher enthalpies of atomization. Reason (R) : Large number of unpaired electrons present in transition elements facilitate strong interatomic interaction and strong bonding between atoms.$ (1) $Both (A) and (R) are correct and (R) is the correct explanation of (A)$ (2) $Both (A) and (R) are correct and (R) is not the correct explanation of (A) .$ (3) $(A) Is correct and (R) is incorrect.$ (4) $(A) Is incorrect and (R) is correct.$ 117. $Identify the metal that forms colourless compounds.$ (1) $Iron (Z = 26)$ (2) $Chromium (Z = 24)$ (3) $Vanadium (Z = 23)$ (4) $Scandium (Z = 21)$ 118. $Most common oxidation state fo Ce (Cerium) are :$ (1) $+3, +4$ (2) $+2, +3$ (3) $+2, +4$ (4) $+3, +5$ 119. $The increase in the atomic radii of the third (5d) series of transition elements is very small, which may be accounted for the filling of ' X' orbitals before ' Y' orbitals. X and Y are X Y$ (1) $4f 5d$ (2) $5f 5d$ (3) $5d 4f$ (4) $4f 4d$ 120. $Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states?$ (1) $3 d^{5} 4 s^{1}$ (2) $3 d^{5} 4 s^{2}$ (3) $3 d^{2} 4 s^{2}$ (4) $3 d^{3} 4 s^{2}$