d- and f-Block Elements PYQs Set 9 (PDF)

Set 9 of 15 · Questions 241-270 of 443

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Mere Teacher · Previous Year Questions JEE Main Chemistry · d- and f-Block Elements · Set 9 (Q241-270)
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241. $Which of the following characteristics of the transition metals is associated with their catalytic activity?$ (1) $Colour of hydrated ions$ (2) $Diamagnetic behaviour$ (3) $Paramagnetic behaviour$ (4) $Variable oxidation states$ 242. $When MnO_{2} and H_{2} SO_{4} is added to a salt (A), the greenish yellow gas liberated as salt (A) is :$ (1) $CaI_{2}$ (2) $NaBr$ (3) $KNO_{3}$ (4) $NH_{4} Cl$ 243. $The formula mass of Mohr's salt is 392 . The iron present in it is oxidised by KMnO_{4} in acid medium. The equivalent mass of Mohr's salt is$ (1) $392$ (2) $31.6$ (3) $278$ (4) $156$ 244. $Which of the following has least tendency to liberate H_{2} from mineral acids ?$ (1) $Cu$ (2) $Mn$ (3) $Ni$ (4) $Zn$ 245. $In following pairs, the one in which both transition metal ions are colourless is :$ (1) $S c^{3 +}, Z n^{2 +}$ (2) $T i^{4 +}, C u^{2 +}$ (3) $V^{2 +}, T i^{3 +}$ (4) $Z n^{2 +}, M n^{2 +}$ 246. $Consider the following reactions K_{2} Cr_{2} O_{7} \to KOH - H_{2} O [A] \to H_{2} SO_{4} - H_{2} O [B] + K_{2} SO_{4} The products [A] and [B], respectively are:$ (1) $K_{2} CrO_{4} and CrO$ (2) $K_{2} CrO_{4} and Cr_{2} O_{3}$ (3) $K_{2} CrO_{4} and K_{2} Cr_{2} O_{7}$ (4) $K_{2} Cr (OH)_{6} and Cr_{2} O_{3}$ 247. $Mn^{2 +} compounds are more stable than Fe^{2 +} compounds towards oxidation to their +3 state, because$ (1) $Mn^{2 +} is more stable with high 3^{rd} ionisation energy$ (2) $Mn^{2 +} is bigger in size$ (3) $Mn^{2 +} has completely filled d-orbitals$ (4) $Mn^{2 +} does not exist.$ 248. $Name the gas that can readily decolourise acidified KMnO4 solution:$ (1) $CO2$ (2) $SO2$ (3) $NO2$ (4) $P2O5$ 249. $In lanthanide series, the element well known to exhibit +4 oxidation state is$ (1) $Lu$ (2) $Ce$ (3) $Pm$ (4) $Nd$ 250. $A and B formed in the following reactions are: CrO_{2} Cl_{2} + 4 NaOH \to A + 2 NaCl + 2 H_{2} O A + 2 HCl + 2 H_{2} O_{2} \to B + 3 H_{2} O$ (1) $A = Na_{2} CrO_{4}, B = CrO_{5}$ (2) $A = Na_{2} Cr_{2} O_{4}, B = CrO_{4}$ (3) $A = Na_{2} Cr_{2} O_{7}, B = CrO_{3}$ (4) $A = Na_{2} Cr_{2} O_{7}, B = CrO_{5}$ 251. $The set of correct statements is: (I) Manganese exhibits +7 oxidation state in its oxide. (II) Ruthenium and Osmium exhibit +8 oxidation in their oxides. (III) Sc shows +4 oxidation state which is oxidizing in nature. (IV) Cr shows oxidising nature in +6 oxidation state.$ (1) $(II)and(III)$ (2) $(I), (II) and (IV)$ (3) $(I) and (III)$ (4) $(II), (III) and (IV)$ 252. $Which of the following statement is not true about interstitial complexes?$ (1) $Small atom like C, H or N are trapped inside crystal lattice$ (2) $They are usually non-stoichiometric$ (3) $They generally \cdot retain metallic conductivity$ (4) $They are chemically very active$ 253. $The pair that has similar atomic radii is:$ (1) $Mn and Re$ (2) $Ti and Hf$ (3) $Sc and Ni$ (4) $Mo and W$ 254. $Which of the following halides react(s) with A g N O_{3} (aq) to give a precipitate that dissolves in N a_{2} S_{2} O_{3} (aq) ?$ (1) $HCl$ (2) $HF$ (3) $HBr$ (4) $HI$ 255. $Lanthanoid ions with 4 f^{7} configuration are : (A) Eu^{2 +} (B) Gd^{3 +} (C) Eu^{3 +} (D) Tb^{3 +} ( E ) Sm^{2 +} Choose the correct answer from the options given below:$ (1) $(A) and (D) only$ (2) $(B) and (C) only$ (3) $(A) and (B) only$ (4) $(B) and (E) only$ 256. $What are X and Y in the following reactions? (i) MnO_{4}^{-} + I^{-} \to H + X (ii) MnO_{4}^{-} + I^{-} \to H 2 O Y$ (1) $I_{2}, IO_{4}^{-}$ (2) $I_{2}, IO_{3}^{-}$ (3) $IO_{3}^{-}, IO_{3}^{-}$ (4) $IO_{3}^{-}, I_{2}$ 257. $Which one of the following ions exhibits d‐d transition and paramagnetism as well?$ (1) $C r O_{4}^{2 -}$ (2) $C r_{2} O_{7}^{2 -}$ (3) $M n O_{4^{-}}$ (4) $M n O_{4}^{2 -}$ 258. $On heating a mixture of common salt and K_{2} Cr_{2} O_{7} in equal amount along with concentrated H_{2} SO_{4} in a test tube, a gas is evolved. Formula of the gas evolved and oxidation state of the central metal atom in the gas respectively are:$ (1) $Cr_{2} O_{2} Cl_{2} and +3$ (2) $CrO_{2} Cl_{2} and +5$ (3) $CrO_{2} Cl_{2} and +6$ (4) $Cr_{2} O_{2} Cl_{2} and +6$ 259. $Given below are two statements: Statement I : Iron (III) catalyst, acidified K_{2} C r_{2} O_{7} and neutral K M n O_{4} have the ability to oxidise I^{-} to I_{2} independently. Statement II: Manganate ion is paramagnetic in nature and involves p π - p π bonding. choose the correct answer from the options.$ (1) $Both statement I and Statement II are true$ (2) $Both statement I and Statement II are false$ (3) $Statement I is true but Statement II is false$ (4) $Statement I is false but Statement II is true$ 260. $The correct order of ionic radii of trivalent ions Y^{3 +}, La^{3 +}, Eu^{3 +}, and Lu^{3 +} is (Y = 39, La = 57, Eu = 63, Lu = 71)$ (1) $Lu^{3 +} < Eu^{3 +} < La^{3 +} < Y^{3 +}$ (2) $La^{3 +} < Eu^{3 +} < Lu^{3 +} < Y^{3 +}$ (3) $Y^{3 +} < Lu^{3 +} < Eu^{3 +} < La^{3 +}$ (4) $Y^{3 +} < La^{3 +} < Eu^{3 +} < Lu^{3 +}$ 261. $Which of the following set of elements do not possess f-electrons?$ (1) $La, U, Lr$ (2) $La, Th, Lr$ (3) $La, Ac, Th$ (4) $Ce, Ac, Th$ 262. $Which of the following statements is wrong regarding lanthanoids?$ (1) $In(III) compounds are predominantly ionic in character.$ (2) $Ln(III) hydroxides are mainly basic in nature.$ (3) $The ionic size of Ln (111) ions decreases with increasing atomic number.$ (4) $Ln (III) compounds are generally colourless.$ 263. $German silver contains which of the following metals?$ (1) $Cu, Zn$ (2) $Fe, Zn$ (3) $Zn, Fe, Ni$ (4) $Cu, Zn, Ni$ 264. $The colour and magnetic nature of manganate ion (MnO_{4}^{2 -}) is$ (1) $green, paramagnetic$ (2) $purple, diamagnetic$ (3) $green, diamagnetic$ (4) $purple, paramagnetic.$ 265. $For decolorization of 1 mole of KMnO4, the moles of H2O2 required is :$ (1) $1/2$ (2) $3/2$ (3) $5/2$ (4) $7/2$ 266. $The oxidation state of chromium in the final product formed in the reaction between KI and acidified K_{2} Cr_{2} O_{7} solution is:$ (1) $+6$ (2) $+3$ (3) $+4$ (4) $+2$ 267. $Consider the hydrated ions of T i^{2 +}, V^{2 +}, T i^{3 +} and S c^{3 +} . The correct order of their spin-only magnetic moments is:$ (1) $V^{2 +} < T^{2 +} < T i^{3 +} < S c^{3 +}$ (2) $S c^{3 +} < Ti^{3 +} < T i^{2 +} < V^{2 +}$ (3) $T i^{3 +} < T i^{2 +} < S c^{3 +} < V^{2 +}$ (4) $S c^{3 +} < T i^{3 +} < V^{2 +} < T i^{2 +}$ 268. $In ammonium-phosphomolybdate, the oxidation state of Mo is +_______$ 269. $The number of 4felectrons in the ground state electronic configuration of G d^{d +} is ____. [Atomic number of Gd = 64]$ 270. $Among CrO, Cr_{2} O_{3} and CrO_{3}, the sum of spin-only magnetic moment values of basic and amphoteric oxides is_____10^{- 2} BM (nearest integer). (Given atomic number of Cr is 24 )$