d- and f-Block Elements PYQs Set 6 (PDF)

Set 6 of 15 · Questions 151-180 of 443

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Mere Teacher · Previous Year Questions JEE Main Chemistry · d- and f-Block Elements · Set 6 (Q151-180)
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151. $The reason for greater range of oxidation states in actinoids is attributed to :$ (1) $The radioactive nature of actinoids$ (2) $Actinoid contraction$ (3) $5f, 6d and 7s levels having comparable energies$ (4) $4f and 5d levels being close in energies$ 152. $The catalyst used in the manufacture of polyethylene is a mixture of$ (1) $Ti, Al (CH_{3})_{3}$ (2) $Ti, CH_{3} MgBr$ (3) $TiCl_{3}, Si (CH_{3})_{4}$ (4) $TiCl_{4}, Al (CH_{3})_{3}$ 153. $Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to$ (1) $Prevent hydrolysis$ (2) $Prevent reduction$ (3) $Prevent breaking$ (4) $Prevent oxidation$ 154. $The effect of lanthanoid contraction in the lanthanoid series of elements by and large means:$ (1) $increase in both atomic and ionic radii$ (2) $decrease in atomic radii and increase in ionic radii$ (3) $decrease in both atomic and ionic radii$ (4) $increase in atomic radii and decrease in ionic radii$ 155. $Which one of the following shows highest magnetic moment?$ (1) $Fe^{2 +}$ (2) $Co^{2 +}$ (3) $Cr^{3 +}$ (4) $Ni^{2 +}$ 156. $MnO_{4}^{2 -}, in acidic medium, disproportionates to :$ (1) $MnO4 -and MnO_{2}$ (2) $Mn_{2} O_{7} and MnO_{2}$ (3) $Mn_{2} O_{7} and MnO$ (4) $MnO_{4}^{-} and MnO$ 157. $Lanthanoid contraction is caused due to :$ (1) $the appreciable shielding on outer electrons by 4ƒ electrons from the nuclear charge$ (2) $the appreciable shielding on outer electrons by 5ƒ electrons from the nuclear charge$ (3) $the same effective nuclear charge from Ce to Lu$ (4) $the imperfect shielding on outer electrons by 4f electrons from the nuclear charge$ 158. $Amongst the following identify the species with an atom in +6 oxidation state.$ (1) $MnO_{4}^{-}$ (2) $Cr(CN)_{6}^{3-}$ (3) $NiF_{6}^{2-}$ (4) $C r O_{2} C l_{2}$ 159. $Which of the following statement concerning lanthanide elements is false$ (1) $All lanthanides are highly dense metals.$ (2) $More characteristic oxidation state of lanthanide elements is + 3.$ (3) $Lanthanides are separated from one another by ion exchange method.$ (4) $Ionic radii of trivalent lanthanides steadily increases with increase in the atomic number.$ 160. $The magnetic moment of a transition metal ion is 15 B.M. Therefore the number of unpaired electrons present in it is$ (1) $4$ (2) $1$ (3) $2$ (4) $3$ 161. $The ‘f’ orbitals are half and completely filled, respectively in lanthanide ions (Given: Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]$ (1) $E u^{2 +} and T m^{2 +}$ (2) $S m^{2 +} and T m^{3 +}$ (3) $T b^{4 +} and Y b^{2 +}$ (4) $D y^{3 +} and Y b^{3 +}$ 162. $Without losing its concentration, Z n C l_{2} solution cannot be kept in contact with$ (1) $Pb$ (2) $Al$ (3) $Au$ (4) $Ag$ 163. $The lanthanide ion that would show colour is:$ (1) $G d^{3 +}$ (2) $S m^{3 +}$ (3) $L a^{3 +}$ (4) $L u^{3 +}$ 164. $Which of the following are correct? (i) V^{2 +} liberates hydrogen from a dilute acid (ii) The earlier members of lanthanide series behave more like aluminium (iii) The 'silver' UK coins are made of Cu / Ni alloy (iv) The maximum oxidation state exhibited by Neptunium is +7$ (1) $(i) (iii) only$ (2) $(ii) (iv) only$ (3) $(i) (iii) (iv) only$ (4) $(i) (ii) (iii) only$ 165. $Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being.$ (1) $lesser energy difference between 5f and 6d than between 4f and 5d orbitals$ (2) $more energy difference between 5f and 6d than between 4f and 5d orbitals$ (3) $more reactive nature of the actinoids than the lanthanoids$ (4) $4f orbitals more diffused than the 5f orbitals$ 166. $Which of the following does not represent property stated against it?$ (1) $Co^{2 +} < Fe^{2 +} < Mn^{2 +} - Ionic size$ (2) $Ti < V < Mn - Number of oxidation states$ (3) $Cr^{2 +} < Mn^{24} < Fe^{24} - paramagnetic behaviour$ (4) $none of the above$ 167. $The spin only magnetic moment of Fe^{2 x} ion (in B.M.) is approximately$ (1) $4$ (2) $7$ (3) $5$ (4) $6$ 168. $What is the stock notation of Manganese dioxide?$ (1) $Mn (I) O_{2}$ (2) $Mn (II) O_{2}$ (3) $Mn (III) O_{2}$ (4) $Mn (IV) O_{2}$ 169. $Which of the following ions is the strongest oxidizing agent? (Atomic Number of Ce 58, Eu = 63, Tb = 65, Lu = 71)$ (1) $Eu^{2 +}$ (2) $Tb^{4 +}$ (3) $Lu^{3 +}$ (4) $Ce^{3 +}$ 170. $Given below are two statement: one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : Size of Bk^{3 +} ion is less than Np^{3 +} ion. Reason R : The above is a consequence of the lanthanoidcontraction. choose the correct answer from the options given below:$ (1) $A is false but R is true$ (2) $Both A and R are true but R is not the correct explanation of A$ (3) $Both A and R are true and R is the correct explanation of A$ (4) $A is true but R is false$ 171. $Amongst T i F_{6}^{2 -}, C o F_{6}^{3 -}, C u_{2} C l_{2} and N i C l_{4}^{2 -}, which are the colourless species? (Atomic number of T i = 22, C o = 27, C u = 29, N i = 28)$ (1) $C o F_{6}^{3 -} and N i C l_{4}^{2 -}$ (2) $T i F_{6}^{2 -} and C u_{2} C l_{2}$ (3) $C u_{2} C l_{2} and N i C l_{4}^{2 -}$ (4) $T i F_{6}^{2 -} and C o F_{6}^{3 -}$ 172. $The correct set of ions (aqueous solution) with same colour from the following is:$ (1) $Sc^{3 +}, Ti^{3 +}, Cr^{2 +}$ (2) $V^{2 +}, Cr^{3 +}, Mn^{3 +}$ (3) $Ti^{4 +}, V^{4 +}, Mn^{2 +}$ (4) $Zn^{2 +}, V^{3 +}, Fe^{3 +}$ 173. $Which of the following is the common oxidation state for 'transition' elements?$ (1) $+3$ (2) $+1$ (3) $+2$ (4) $+4$ 174. $Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?$ (1) $C u C l_{2}$ (2) $AgCl$ (3) $ZnCl$ (4) $C u_{2} C l_{2}$ 175. $The incorrect statement(s) among (a) - (c) is (are) A. W(VI) is more stable than Cr (VI) B. In presence f HCl, permanganate titrations provide satisfactory results. C. Some lanthanoid oxides can be used as phosphors.$ (1) $(A) and (B) only$ (2) $(A) only$ (3) $(B) and (C) only$ (4) $(B) only$ 176. $When 35 mL of 0.15 M lead nitrate solution is mixed with 20 mL of 0.12 M chromic sulphate solution, \times 10^{- 5} moles of lead sulphate precipitate out. (Round off to the Nearest Integer).$ 177. $The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of CO_{2} . The sum of spin-only magnetic moment values of A and B is _______B.M. (Nearest integer) [Given atomic number : C : 6, Na : 11, O : 8, Fe : 26, Cr : 24]$ 178. $Consider the following list of reagents : Acidified K_{2} C r_{2} O_{7}, alkaline K M n O_{4}, C u S O_{4}, H_{2} O_{2}, C l_{2}, O_{3}, F e C l_{3}, H N O_{3} and N a_{2} S_{2} O_{3} . The total number of reagents that can oxidise aqueous iodide to iodine is :$ 179. $In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is (+)$ 180. $In the titration of K M n O_{4} and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is_____$