Transition Elements (3d Series) — Practice Questions

Free NEET Chemistry multiple-choice questions on Transition Elements (3d Series). Attempt each question and reveal the answer with a full explanation.

The melting points of Zn, Cd, and Hg are low because: Their d-subshells are completely filled They have high ionization enthalpies Their atomic sizes are very large They have no s-electrons The aqueous solution of which of the following ions will be green in color? Ni 2+ Cu 2+ Mn 2+ Fe 3+ The E values for Ti, V, Cr and Mn are -1.63, -1.13, -0.90 and -1.18 V respectively. Which of these is the strongest reducing agent? Ti V Cr Mn Which of the following electronic configurations represents an element with the highest magnetic moment? 3d 5 4s 2 3d 3 4s 2 3d 7 4s 2 3d 10 4s 1 Which of the following properties is NOT typical for transition elements? High tendency to form ionic compounds in low oxidation states Formation of colored ions Variable oxidation states Paramagnetic behavior The electronic configuration of Silver ( Ag, Z=47 ) in its ground state is: [Kr]4d 10 5s 1 [Kr]4d 9 5s 2 [Ar]4d 10 5s 1 [Xe]4d 10 5s 1 Identify the element in the 3d series which has the lowest first ionization enthalpy. Sc Ti Zn Cu Which of the following oxides of Vanadium is amphoteric in nature and reacts with both acids and alkalies? V 2O 5 V 2O 3 VO VO 2 Why is Ce 4+ a strong oxidizing agent, even though it has a stable noble gas configuration [Xe]4f 0 ? It has a high tendency to revert to the most stable +3 state It is a radioactive element Its size is very small It has low hydration energy The E value for Mn 3+ /Mn 2+ couple is much more positive than that for Cr 3+ /Cr 2+ or Fe 3+ /Fe 2+ . This is because: Mn 2+ has a stable d 5 configuration Mn 3+ has a stable d 4 configuration Mn has a higher atomic number than Cr Mn has higher enthalpy of atomization Iron becomes 'passive' and stops reacting when treated with concentrated Nitric acid ( HNO 3 ). This is due to the formation of: A thin protective layer of Fe 3O 4 A layer of Ferric Nitrate A layer of Ferrous Nitrate Evolution of NO 2 gas which blocks the surface Calculate the spin-only magnetic moment of Mn 4+ ion ( Z=25 ). 3.87 BM 4.90 BM 5.92 BM 1.73 BM The electronic configuration of Cerium ( Z=58 ) in its +4 oxidation state is: [Xe] [Xe]4f 1 [Xe]4f 2 [Xe]5d 1 In the 3d series, which element has the lowest enthalpy of atomization? Zn Mn Cu Sc Across the 3d series, the atomic radii decrease significantly from Sc to Cr, but the decrease is very small from Fe to Ni. The reason for this is: Shielding of 3d electrons balances the increase in nuclear charge Increases in the number of 4s electrons Formation of metallic bonds is stronger in the middle The 3d subshell is completely empty Which pair of elements has almost the same atomic radii due to the shielding effect and lanthanoid contraction? Nb and Ta Sc and Y Ti and Zr Mo and Mn The E (M 2+ /M) value for Zinc is significantly more negative than the general trend in the 3d series because of: The stability of the d 10 electronic configuration in Zn 2+ High enthalpy of atomization Low hydration enthalpy of Zn 2+ High third ionization enthalpy Which of the following transition metal halides is a volatile liquid at room temperature? TiCl 4 TiF 4 VCl 3 CrCl 3 The compound Mercury(I) chloride ( Hg 2Cl 2 ), also known as calomel, exists as a dimer because: The Hg-Hg bond is formed between two Hg + ions Mercury cannot exist in +1 oxidation state It is a covalent network solid It is a gas at room temperature The element with the highest enthalpy of atomization in the entire transition series (3d, 4d, and 5d) is: Tungsten ( W ) Iron ( Fe ) Osmium ( Os ) Chromium ( Cr ) Calculate the spin-only magnetic moment of Pr 3+ ( Z=59 ). 3.58 BM 2.83 BM 1.73 BM 4.90 BM The stability of Cr 3+ in aqueous solution and coordination complexes is attributed to: A half-filled t 2g subshell ( t 2g 3 ) A completely filled e g subshell The 3d 5 configuration Large hydration enthalpy of Cr 2+ The density of transition metals generally increases across a period. Which of the following is the correct reason for the decrease in density from Copper ( Cu ) to Zinc ( Zn )? A sudden increase in atomic volume for Zinc A decrease in the atomic mass of Zinc Zinc has a more compact crystal lattice Zinc has a higher enthalpy of atomization Which of the following transition metals is most likely to form a interstitial hydride easily? Pd Fe Mn Zn Which element in the 3d series has the highest second ionization enthalpy ( IE 2 )? Cr Cu Mn Zn What is the oxidation state of Iron in the 'Brown Ring' complex [Fe(H 2O) 5(NO)]SO 4 ? +1 +2 +3 0 The oxide of a transition metal which shows electrical conductivity similar to that of metallic copper is: ReO 3 TiO 2 V 2O 3 Cr 2O 3 Which of the following oxides is used in the manufacturing of magnetic recording tapes? CrO 2 Fe 2O 3 MnO 2 TiO 2 When titanium tetrachloride ( TiCl 4 ) comes into contact with moist air, it forms dense white fumes. This property is used in smoke screens and is due to the formation of: TiO 2 and HCl Ti(OH) 4 only TiCl 3 and Cl 2 TiO and ClO 2 Among the silver halides, AgF is highly soluble in water while AgCl , AgBr , and AgI are insoluble. This is because: The hydration enthalpy of F - is high enough to overcome the lattice enthalpy Silver fluoride is a purely covalent compound The lattice enthalpy of AgF is much higher than that of AgI Fluorine is the most electronegative element The Nd:YAG laser, widely used in medicine and industry, uses which of the following elements as the dopant? Neodymium Nickel Niobium Neon The enzyme nitrogenase, which catalyzes the conversion of atmospheric N 2 to ammonia in legumes, contains which transition metal(s)? Mo and Fe Cu and Zn Mg and Mn Co and Ni The standard reduction potential E (Fe 3+ /Fe 2+ ) is +0.77 V . This value indicates that: Fe 3+ is a moderately strong oxidizing agent compared to H + Fe 2+ is more stable than Fe 3+ in all conditions Fe 2+ cannot be oxidized to Fe 3+ by any common reagent The reduction of Fe 3+ to Fe 2+ is a non-spontaneous process Gadolinium ( Gd ) is used in nuclear reactors primarily as a: Neutron absorber (control rod material) Coolant Nuclear fuel Moderator Which of the following ions has the highest magnetic moment? Fe 3+ Cr 3+ Co 3+ Ni 2+ Calculate the spin-only magnetic moment for the Ti 2+ ion ( Z=22 ). 2.83 BM 1.73 BM 3.87 BM 4.90 BM Raney Nickel, used as a catalyst in organic hydrogenation reactions, is prepared by: Treating a Ni-Al alloy with concentrated NaOH Reducing NiO with H 2 gas at high temperature Electrolysis of NiSO 4 solution Decomposition of Ni(CO) 4 Scandium ( Z=21 ) is often not considered a 'typical' transition metal because: Its only common ion, Sc 3+ , has a completely empty d -subshell It has a very high melting point compared to other 3d metals It does not form any coordination compounds It is found in the p -block of the periodic table The highest possible oxidation state of +8 is shown by which of the following transition metals? Ruthenium and Osmium Manganese and Technetium Iron and Cobalt Platinum and Iridium Vanadium pentoxide ( V 2O 5 ) is amphoteric. It reacts with alkalies to give: VO 4 3- (orthovanadate) VO 2+ (vanadyl) VO 2 + (pervanadyl) V 3+ ions The catalyst used in the Wacker process for the oxidation of ethyne to ethanal is: PdCl 2 V 2O 5 TiCl 4 FeCl 3 Which of the following transition metals is present in Wilkinson's catalyst, used for the hydrogenation of alkenes? Rhodium Platinum Palladium Iridium In the 3d transition series, which element has the highest first ionization enthalpy ( IE 1 )? Zinc Scandium Copper Manganese What is the oxidation state of Iron in Ferrocene, [Fe(C 5H 5) 2] ? +2 0 +3 +1 In the 3d series, which element shows the lowest enthalpy of sublimation? Zinc Manganese Copper Scandium The catalytic activity of transition metals is due to their ability to: Show variable oxidation states and form complexes Highly stable electronic configurations High melting points Large atomic size The color of the [Ti(H 2O) 6] 3+ complex is purple. This is due to an electronic transition from: t 2g to e g e g to t 2g s to d d to s Identify the element in the 3d series which has the maximum value of IE 3 . Zinc Manganese Copper Iron Anhydrous Copper(II) sulfate is white, while hydrated Copper(II) sulfate ( CuSO 4 5H 2O ) is blue. This is because: In the anhydrous form, d-d transition is not possible in the absence of ligands Hydration changes the oxidation state of Copper Anhydrous Copper(II) sulfate is diamagnetic Water molecules absorb blue light Which of the following transition metals has the highest melting point among the 3d series elements? Chromium Iron Manganese Vanadium In the 3d transition series, the enthalpy of atomization is highest for which element? Vanadium Scandium Manganese Copper Which of the following statements regarding the stability of oxidation states in the 4d and 5d series is correct? Higher oxidation states are more stable for heavier transition elements. Lower oxidation states are more stable for heavier transition elements. The stability of the +2 state increases down the group. Tungsten is a better oxidizing agent than Chromium in the +6 state. Which of the following oxides of Chromium is the most basic? CrO Cr 2O 3 CrO 3 CrO 2 Which of the following properties of transition elements is primarily responsible for their ability to form non-stoichiometric compounds? Variable oxidation states and lattice defects Small atomic size High ionization enthalpy Completely filled d-orbitals Why is the first ionization enthalpy ( IE 1 ) of 5d elements generally higher than that of 3d and 4d elements? Greater effective nuclear charge due to poor shielding by 4f electrons Larger atomic size of 5d elements Completely filled d -orbitals in 5d elements Higher shielding effect of 5s electrons Which of the following transition metal ions is the most stable in an aqueous solution with a d 3 configuration? Cr 3+ V 2+ Ti + Mn 4+ Transition elements are known for forming many coordination compounds because of: Small size, high ionic charge, and availability of d-orbitals Large size and low ionic charge Completely filled d-orbitals High electronegativity Which of the following transition metals has the highest density in the 5d series? Iridium Tungsten Gold Platinum The purple color of [Ti(H 2O) 6] 3+ disappears on heating because: Water molecules are lost, removing the crystal field. Titanium is oxidized to Ti 4+ . Titanium is reduced to Ti 2+ . The complex becomes tetrahedral. Four successive members of the first row transition elements are listed below with their atomic numbers. which one of them is expected to have the highest third ionization enthalpy :- Vanadium (Z = 23) Manganese (Z = 25) Chromium (Z = 24) Iron (Z = 26) Which one of the following ions is the most stable in aqueous solution? (At.No. Ti = 22, V =23, Cr =24, Mn =25) V 3+ Ti 3+ Mn 3+ Cr 3+ Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states ? 3d 2 4s 2 3d 3 4s 2 3d 5 4s 1 3d 5 4s 2 Magnetic moment 2.83 BM is given by which of the following ions ? (At. nos. Ti = 22, Cr = 24, Mn = 25, Ni = 28):- Ti 3+ Ni 2+ Cr 3+ Mn 2+ Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code : iv i ii iii i ii iii iv iv v ii i iii v i ii Which one of the following ions exhibits d-d transition and paramagnetism as well? MnO4 - Cr2O7 2- CrO4 2- MnO4 2- The calculated spin only magnetic moment of Cr 2+ ion is 4.90 BM 5.92 BM 2.84 BM 3.87 BM Identify the correct statement from the following : Blister copper has blistered appearance due to evolution of CO2 . Vapour phase refining is carried out for Nickel by Van Arkel method. Pig iron can be moulded into a variety of shapes. Wrought iron is impure iron with 4% carbon. Which of the following pairs of elements has nearly the same atomic radii due to the lanthanoid contraction? Nb and Ta Zr and Nb Mo and W Ti and Zr Identify the incorrect statement. The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes. Interstitial compounds are those that are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals. The oxidation states of chromium in CrO4 2- and Cr2O7 2- are not the same. Cr 2+ ( d 4 ) is a stronger reducing agent than Fe 2+ ( d 6 ) in water. Which of the following statements are INCORRECT? A. All the transition metals except scandium form MO oxides which are ionic. B. The highest oxidation number corresponding to the group number in transition metal oxides is attained in Sc2O3 to Mn2O7 . C. Basic character increases from V2O3 to V2O4 to V2O5 . D. V2O4 dissolves in acids to give VO4 3- salts. E. CrO is basic but Cr2O3 is amphoteric. Choose the correct answer from the options given below: A and E only B and D only C and D only B and C only The reaction that does NOT take place in a blast furnace between 900 K to 1500 K temperature range during extraction of iron is : Fe2O3 + CO -> 2FeO + CO2 FeO + CO -> Fe + CO2 C + CO2 -> 2CO CaO + SiO2 -> CaSiO3 The E° value for the Mn 3+ /Mn 2+ couple is more positive than that of Cr 3+ /Cr 2+ or Fe 3+ /Fe 2+ due to change of d 5 to d 4 configuration d 5 to d 2 configuration d 4 to d 5 configuration d 3 to d 5 configuration ‘Spin only’ magnetic moment is same for which of the following ions? A. Ti 3+ B. Cr 2+ C. Mn 2+ D. Fe 2+ E. Sc 3+ Choose the most appropriate answer from the options given below. B and D only A and E only B and C only A and D only Match List I with List II : array llll ; & List I (Transition metal/compound/complex) & ; & List II (Catalytic Role) A. & V2O5 & I. & Preparation of ammonia from N2/H2 mixture B. & Fe & II. & Polymerisation of alkynes C. & PdCl2 & III. & Preparation of H2SO4 and SO2 D. & Ni complex & IV. & Oxidation of ethyne to ethanal array Choose the correct answer from the options given below. A-III, B-IV, C-I, D-II A-III, B-I, C-IV, D-II A-II, B-I, C-IV, D-III A-IV, B-I, C-III, D-II Which of the following elements has the highest third ionization enthalpy ( IE 3 ) in the 3d transition series? Zinc ( Zn ) Manganese ( Mn ) Iron ( Fe ) Copper ( Cu ) The electronic configuration of Terbium ( Z=65 ) is: [Xe]4f 9 6s 2 [Xe]4f 7 5d 1 6s 2 [Xe]4f 8 5d 1 6s 2 [Xe]4f 10 6s 1 What is the correct order of the first ionization enthalpies ( IE 1 ) for the following elements? Zn > Cu > Mn > Cr Mn > Cr > Cu > Zn Cu > Zn > Mn > Cr Zn > Mn > Cu > Cr In the 3d series, why does Chromium ( Cr 2+ ) act as a reducing agent while Manganese ( Mn 3+ ) acts as an oxidizing agent, even though both have a d 4 configuration? Change from d 4 to d 3 in Cr 2+ results in a stable t 2g 3 configuration Cr is more electronegative than Mn The 3d 5 configuration of Mn 2+ is less stable than 3d 3 Hydration enthalpy of Cr 2+ is lower than Mn 3+ The violet color of the [Ti(H 2O) 6] 3+ complex is attributed to: d-d transition Charge transfer from ligand to metal Charge transfer from metal to ligand Presence of f -electrons The electronic configuration of Palladium ( Pd, Z=46 ) is unique among d -block elements because it is: [Kr]4d 10 5s 0 [Kr]4d 9 5s 1 [Kr]4d 8 5s 2 [Xe]4d 10 5s 0 The E (M 2+ /M) value for which of the following elements is surprisingly more negative than the general trend due to the stability of the half-filled d -subshell? Mn Fe Cr Co Mercury is the only transition metal that is liquid at room temperature. This is primarily attributed to: Relativistic contraction of 6s orbital leading to weak metallic bonding High ionization enthalpy and small atomic size Completely filled d -orbitals resulting in no covalent character High vapor pressure and low boiling point Which of the following statements is TRUE regarding the stability of the +6 oxidation state in Group 6 ( Cr, Mo, W )? The stability of the +6 state increases down the group ( Cr < Mo < W ) The stability of the +6 state decreases down the group ( Cr > Mo > W ) Only Chromium shows a stable +6 oxidation state All three elements are equally strong oxidizing agents in the +6 state The disproportionation of Cu +(aq) into Cu 2+ (aq) and Cu(s) is spontaneous because: The hydration enthalpy of Cu 2+ is much more negative than that of Cu + Cu + has a stable d 10 configuration Copper is a noble metal and prefers the metallic state The lattice energy of CuCl is very low In the structure of hydrated copper sulfate, CuSO 4 5H 2O , how many water molecules are directly coordinated to the Cu 2+ ion? 4 5 6 2 Comparing the ionic radii of Cu 2+ and Zn 2+ , which of the following is correct? Cu 2+ is larger than Zn 2+ due to lower effective nuclear charge Zn 2+ is larger than Cu 2+ due to the completed d 10 shell and increased shielding They have identical radii because they are adjacent in the series Cu 2+ is larger because it is paramagnetic What is the correct reason for the positive value of the standard electrode potential E (Cu 2+ /Cu) = +0.34 V ? High enthalpy of atomization and low enthalpy of hydration Low enthalpy of atomization and high enthalpy of hydration High ionization enthalpy and high enthalpy of hydration Low ionization enthalpy and low enthalpy of atomization The stability of the +1 oxidation state increases in the sequence: Cu < Ag < Au Au < Ag < Cu Ag < Cu < Au Cu < Au < Ag In the manufacture of Sulphuric acid by the Contact process, the oxidation of SO 2 to SO 3 involves the intermediate formation of: V 2O 4 V 2O 3 VO V 2O 5 In the context of lanthanoid contraction, which of the following pairs of elements has nearly identical atomic radii? Zr and Hf Ti and Zr Nb and W Mo and Nb Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Generally, 3d transition metals have high melting points. Reason R: Involvement of 3d-electrons in addition to 4s-electrons in the interatomic metallic bonding. In light of the above statements, choose the most appropriate answer from the options given below: Both A and R are correct and R is the correct explanation of A Both A and R are correct and R is NOT the correct explanation of A A is correct but R is not correct. A is not correct but R is correct The reagent used in the 'Silver Mirror Test' for aldehydes involves which transition metal complex? [Ag(NH 3) 2] + [Ag(CN) 2] - AgNO 3 [Cu(NH 3) 4] 2+ The transition metal that does not show variable oxidation states is: Scandium Iron Manganese Copper In the contact process, which oxide of a transition metal is used as a catalyst for the oxidation of SO 2 to SO 3 ? V 2O 5 MnO 2 Cr 2O 3 Fe 2O 3 Which of the following transition metals does NOT react with mineral acids to liberate H 2 gas? Copper Zinc Iron Manganese Which of the following properties is NOT characteristic of transition elements? They show high reactivity towards water They form colored ions They show variable oxidation states They form interstitial compounds Which of the following transition metal oxides is most likely to be used as a pigment in white paint? TiO 2 MnO 2 Cr 2O 3 V 2O 5 Which of the following transition metal ions is diamagnetic? Sc 3+ Ti 3+ V 3+ Cr 3+ In which of the following pairs is the first element's size larger than the second, despite belonging to the same group in the d -block? Sc > Ti Zr > Hf Nb > Ta Mo > W The catalyst used in the manufacture of polyethylene by the Ziegler-Natta process is: TiCl 4 and (C 2H 5) 3Al V 2O 5 PdCl 2 Fe 2O 3 Which of the following transition metals has the electronic configuration [Ar]3d 5 4s 1 ? Chromium ( Cr ) Manganese ( Mn ) Iron ( Fe ) Vanadium ( V ) Why do transition elements form interstitial compounds? Small atoms like H, C, N can fit into the voids of their crystal lattices Transition metals are very reactive They have low ionization enthalpies They have very high melting points Which of the following 3d series ions has the largest number of unpaired electrons? Fe 3+ Co 2+ Ni 2+ Cu 2+ The catalytic activity of transition metals and their compounds is ascribed to: Their ability to adopt variable oxidation states Their high melting points Their magnetic properties Their chemical reactivity with water Transition metals are often used as heterogeneous catalysts because they provide: A surface for reactant molecules to adsorb High activation energy for reactions Large quantities of heat to the reaction Solubility to the gaseous reactants The catalyst used in the 'Contact Process' for the oxidation of SO 2 to SO 3 is: V 2O 5 MnO 2 Fe Pt Which of the following sets of elements are not strictly regarded as transition elements because of their completely filled d -orbitals in both ground state and common oxidation states? Zn, Cd, Hg Sc, Y, La Cu, Ag, Au Fe, Co, Ni What is the correct ground state electronic configuration of Copper ( Z=29 )? [Ar]3d 10 4s 1 [Ar]3d 9 4s 2 [Ar]3d 8 4s 2 4p 1 [Ar]4s 2 3d 9 Which of the following factors is primarily responsible for the stability of the +2 oxidation state of Manganese ( Mn 2+ )? Half-filled d -subshell ( 3d 5 ) Completely filled s -subshell Low ionization enthalpy High enthalpy of hydration Which of the following transition metals shows the highest melting point in its respective series? Tungsten (W) Chromium (Cr) Iron (Fe) Manganese (Mn) Which of the following 3d series ions is diamagnetic? Sc 3+ Ti 3+ V 3+ Cr 3+ Which of the following oxides of Chromium is purely basic? CrO Cr 2O 3 CrO 3 CrO 5 The catalytic property of transition metals like Platinum ( Pt ) and Palladium ( Pd ) in hydrogenation reactions is primarily due to their ability to: Adsorb reactant molecules on their surface Act as strong oxidizing agents Change their oxidation state from +2 to +4 Form ionic hydrides easily When the vapors of chromyl chloride ( CrO 2Cl 2 ) are passed into a solution of NaOH , the resulting yellow solution is due to the formation of: Na 2CrO 4 Na 2Cr 2O 7 Cr(OH) 3 NaCl The transition element that shows the maximum number of oxidation states is: Mn Cr Fe V Chromium trioxide ( CrO 3 ) is a/an: Acidic oxide Basic oxide Amphoteric oxide Neutral oxide The magnetic moment of a transition metal ion is found to be 5.92 BM. The number of unpaired electrons present in it is: 5 4 3 6 Gold ( Au ) and Platinum ( Pt ) are dissolved by which of the following reagents? Aqua Regia Concentrated HNO 3 Concentrated H 2SO 4 A mixture of HCl and H 2SO 4 Which of the following transition metals shows a +1 oxidation state frequently due to the stability of the d 10 configuration? Cu Sc Ti Fe Which of the following elements is used as a catalyst in the Haber-Bosch process for the synthesis of ammonia? Iron ( Fe ) Nickel ( Ni ) Vanadium ( V ) Copper ( Cu ) Which transition metal is an essential component of Vitamin B 12 ? Cobalt Iron Zinc Magnesium Which silver salt is used in black and white photography due to its sensitivity to light? AgBr AgNO 3 Ag 2SO 4 AgClO 4 Samarium-Cobalt ( SmCo 5 ) is a material famous for its use in: High-strength permanent magnets Refractory ceramics Nuclear fuel rods Semiconducting chips The alloy 'German Silver' contains which of the following sets of metals? Cu, Zn, Ni Cu, Zn, Ag Cu, Sn, Al Fe, Cr, Ni Which of the following ions is diamagnetic in its ground state? Sc 3+ Ti 3+ Cr 3+ V 3+ Which of the following transitions metal ions has the maximum magnetic moment? Fe 3+ Cu 2+ Co 2+ Ni 2+ The correct order of shielding effect of electrons in different orbitals is: s > p > d > f f > d > p > s p > s > d > f d > f > s > p Which of the following is an example of a non-stoichiometric compound formed by transition metals? Fe 0.94 O NaCl H 2O CO 2 The highest oxidation state known for any transition metal is +8 . Which pair of elements shows this state? Os, Ru Mn, Cr Fe, Co W, Mo Which of the following ions is expected to be colorless in aqueous solution? Sc 3+ Ti 3+ V 3+ Cr 3+ In the Ostwald's process for the manufacture of Nitric acid, which transition metal-based catalyst is used for the oxidation of Ammonia? Platinum-Rhodium gauze Vanadium pentoxide Finely divided Iron Nickel powder Which of the following ions has the lowest value of ionic radius? Cr 3+ V 3+ Ti 3+ Sc 3+ Which of the following elements has the electronic configuration [Xe] 4f 14 5d 10 6s 1 ? Gold Platinum Silver Mercury The melting point of transition metals increases to a maximum and then decreases. Which of the following 3d series elements has the highest melting point? Chromium Iron Nickel Manganese The magnetic moment of La 3+ ( Z=57 ) is: 0 BM 1.73 BM 2.84 BM 4.90 BM The catalytic property of transition metals is often associated with their ability to adopt multiple oxidation states. In the decomposition of H 2O 2 , which catalyst is commonly used? MnO 2 V 2O 5 Fe Cu Which of the following statements about interstitial compounds is correct? They are chemically inert They are non-stoichiometric They have high melting points All of the above The aqueous solution containing which one of the following ions will be colourless - [Atomic number : Sc = 21, Fe = 26, Ti = 24, Mn = 25] Fe 2+ Mn 2+ Ti 3+ Sc 3+ In which of the following pairs are both the ions coloured in aqueous solution [At. No. : Sc = 21, Ti = 22, Ni = 28, Cu = 29, Co = 27] Ni 2+ , Ti 3+ Sc 3+ , Ti 3+ Sc 3+ , Co 2+ Ni 2+ , Cu + Which of the following statements about the interstitial compounds is incorrect? They retain metallic conductivity They are chemically reactive They are much harder than the pure metal They have higher melting points than the pure metal Iron carbonyl, Fe(CO)5 is Trinuclear Mononuclear Tetranuclear Dinuclear Which one is malachite from the following? CuCO3.Cu(OH)2 CuFeS2 Cu(OH)2 Fe3O4 Match List-I with List-II. array ll List-I (Ores) & List-II (Composition) (a) Haematite & (i) Fe3O4 (b) Magnetite & (ii) ZnCO3 (c) Calamine & (iii) Fe2O3 (d) Kaolinite & (iv) [Al 2 (OH) 4 Si 2 O 5 ] array Choose the correct answer from the options given below: (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv) (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii) (a)-(i), (b)-(iii), (c)-(ii), (d)-(iv) (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv) The stability of Cu 2+ is more than Cu+ salts in aqueous solution due to First ionisation enthalpy Enthalpy of atomization Hydration energy Second ionisation enthalpy The calculated ‘spin-only’ magnetic moment of Ti 2+ (3d 2 ) is : 3.87 BM 4.90 BM 2.84 BM 5.92 BM Calculate the spin-only magnetic moment of M 2+ ion in aqueous solution if its atomic number is 27. 3.87 BM 4.90 BM 2.84 BM 5.92 BM Which of the following oxides is amphoteric in nature? V 2O 5 CrO 3 Mn 2O 7 CrO The atomic radii of Zr ( Z=40 ) and Hf ( Z=72 ) are almost identical because of: Lanthanoid contraction Actinoid contraction Diagonal relationship Belonging to the same group Which electronic configuration corresponds to Gadolinium ( Z=64 )? [Xe] 4f 7 5d 1 6s 2 [Xe] 4f 8 6s 2 [Xe] 4f 7 5d 0 6s 2 [Xe] 4f 6 5d 2 6s 2 Identify the incorrect statement regarding interstitial compounds. They are chemically very reactive They have high melting points They retain metallic conductivity They are very hard Which of the following 3d series transition metal has the lowest enthalpy of atomization? Zn Cu Sc Fe Which of the following elements has the highest density among the 3d transition series? Cu Fe Ni Zn The stability of Cu 2+ (aq) is more than Cu +(aq) due to: Much more negative hydration enthalpy of Cu 2+ Higher second ionization enthalpy of Cu The larger size of Cu 2+ Lower lattice energy of Cu 2+ Among the following, which one is the strongest reducing agent in the 3d series? Cr 2+ Mn 3+ Ti 2+ Fe 2+ The enthalpy of atomization is lowest for which of the following elements? Zn Cu Sc Cr The E (M 2+ /M) value for copper is positive ( +0.34 V ). What does this indicate? Copper does not liberate H 2 from acids Copper is a very strong reducing agent Copper is easily oxidized by H + ions Copper is more reactive than hydrogen The spin-only magnetic moment of Cr 2+ ion is: 4.90 BM 3.87 BM 5.92 BM 2.84 BM Which transition metal ion among the following is most stable in aqueous solution? Cr 3+ V 3+ Ti 3+ Mn 3+ Which of the following 3d series elements shows only the +3 oxidation state in its compounds? Sc Ti Zn Cu The highest oxidation state of 7+ is shown by: Mn Tc Re All of these The incorrect statement among the following is: Cu 2+ is more reducing than Fe 2+ Cr 2+ is reducing while Mn 3+ is oxidizing Ti 2+ is a reducing agent Mn 2+ is more stable than Mn 3+ The 'butterfly' structure is associated with which of the following compounds? CrO 5 K 2Cr 2O 7 MnO 2 CrO 3 In the 3d series, which element has the highest enthalpy of atomization? Vanadium ( V ) Manganese ( Mn ) Chromium ( Cr ) Iron ( Fe ) Which of the following pairs of elements has the same atomic radius due to lanthanoid contraction? Nb and Ta Zr and Nb Mo and W Ti and Zr Cu + ion is not stable in aqueous solution because it undergoes disproportionation. The products are: Cu 2+ and Cu Cu 2+ and H 2 CuO and Cu Cu(OH) 2 and Cu Which of the following 3d series elements has the highest melting point? Chromium ( Cr ) Iron ( Fe ) Manganese ( Mn ) Copper ( Cu ) The magnetic moment of Gd 3+ ( Z=64 ) is approximately: 7.9 BM 8.9 BM 6.9 BM 5.9 BM The E (M 2+ /M) value for which of the following transition metals in the 3d series is the most negative? Titanium Manganese Zinc Iron Which of the following 3d series elements exhibits the highest second ionization enthalpy ( IE 2 )? Cu Cr Zn Mn The electronic configuration of transition element 'X' in +3 oxidation state is [Ar]3d 5 . What is its atomic number? 26 25 24 27 Identify the element in the 3d series that shows a sharp dip in the melting point graph despite having a high number of unpaired electrons. Manganese Chromium Iron Vanadium Which of the following ions is paramagnetic and has a 'spin-only' magnetic moment of 1.73 BM ? VO 2+ Sc 3+ Cu + Zn 2+ Which of the following transition metal ions has the highest enthalpy of hydration? Cu 2+ Ni 2+ Co 2+ Fe 2+ Which of the following products is formed when Cu 2+ reacts with an excess of Potassium Iodide ( KI )? Cu 2I 2 + I 2 CuI 2 K[CuI 4] CuI + K 2I The spin-only magnetic moment of Ni 2+ ( Z=28 ) in aqueous solution is: 2.83 BM 1.73 BM 3.87 BM 4.90 BM The E (M 2+ /M) value for nickel is more negative than expected. This is primarily due to its: High negative enthalpy of hydration Low enthalpy of atomization High second ionization enthalpy Low sublimation energy What is the oxidation state and geometry of the chromium atom in the chromyl chloride ( CrO 2Cl 2 ) molecule? +6 , Tetrahedral +6 , Square planar +4 , Tetrahedral +3 , Trigonal bipyramidal Identify the element in the 3d series that exhibits the highest density. Copper ( Cu ) Iron ( Fe ) Zinc ( Zn ) Scandium ( Sc ) The transition metal ion which has the smallest ionic radius among the following is: Fe 3+ Fe 2+ Mn 2+ Cr 3+ Calculate the spin-only magnetic moment of V 3+ ( Z=23 ) in Bohr Magnetons (BM). 2.83 BM 1.73 BM 3.87 BM 4.90 BM