Transition Elements Mock Test

TRANSITION ELEMENTS MOCK TEST SECTION - I : STRAIGHT OBJECTIVE TYPE 1. In which compound does vanadium have an oxidation number of +4? (A) NH4 VO2 (B) K4[V(CN)6] (C) VSO4 (D) VOSO4 2. In which of the following oxoanion the oxidation state of central atom is not same as that of its group number in the periodic table? (A) MnO4– (B) Cr2O7–2 (C) VO43– (D) FeO42– 3. Which of the following statements is incorrect? (A) Transition elements exhibit higher enthalpies of atomization as they have stonger interatomic interaction. (B) IE2 of 23V< 24Cr > 25Mn and 28Ni < 29Cu > 30Zn. (C) Ni(II) compounds are more stable than Pt(II) where as Pt (IV) compounds are more stable than Ni(IV). (D) The elements which give the greatest number of oxidation states do not occur in or near the middle of the series. 4. At 300°C, FeCl3 : (A) Decomposes into FeCl2 and Cl2 (C) Sublimes to give liquid FeCl3 5. (B) Decomposes into Fe and Cl2 (D) Sublimes to give gaseous dimer (FeCl3)2 + + H H Fusion  [X]  [Y]  [Z] FeCr2O4 + Na2CO3 + O2  H 2O H 2O 2 Which of the following statements are true for compounds [X], [Y] and [Z] ? (A) In all three compounds, the chromium is in +6 oxidation state. (B) [Z] is a deep-blue violet coloured compound which decomposes rapidly in aqueous solution into Cr+3 and dioxygen. (C) Saturated solution of [Y] gives bright orange compound, chromic anhydride, with conc. H2SO4 (D) All of the above 6. FeCl3.6H2O + C(CH3)2(CH3O)2  Products Reaction product are : (A) FeCl3, CH3OH and CH3COCH3 (C) FeCl2, HCl and CH3COCH3 (B) (CH3O)3Fe, HCl and H2O (D) Fe(OH)3, FeCl3 and CH3COCH3 SECTION - II : MULTIPLE CORRECT ANSWER TYPE 7. 2– – I II Pyrolusite is MnO2 used to prepare KMnO4. Steps are, MnO2   MnO4   MNO4 . Stesp I and II are respectively : (A) fuse with KOH/ air and electrolytic oxidation (B) fuse with KOH/KNO3 and electrolytic oxidation (C) fuse with conc. HNO3/air and electrolytic reduction (D) dissolve in H2O and oxidation 8. Which of the following chemical reaction(s) is(are) involed in the developing of photographic plate? (A) C6H4(OH)2 + 2AgBr  2Ag + C6H4O2 + 2HBr (B) AgBr + 2Na2S2O3  Na3[Ag(S2O3)2] + NaBr (C) AgBr + 2NH3(aq)  [Ag(NH3)2]Br (D) 2AgBr + Na2S2O3  Ag2S2O3 + 2NaBr 9. The hydrated cupric chloride is strongly heated. Which of the following statement(s) is (are) correct for this : (A) It is reduced to Cu2Cl2 (B) Cupric oxide is formed along wiht Cu2Cl2 (C) Only Cl2 is liberated (D) Cl2 and HCl both are liberated 10 Potassium manganate (K2MnO4) is formed. When : (A) cuprous oxide reacts iwth alkaline KMnO4 solution (B) manganese dioxideis fused with K2CO3 in presence of KNO3. (C) formaldehyde reacts with potassium permanganate in presence of concentrated potassium hydroxide solution. (D) potassium permanganate is heated with potassium hydroxide. SECTION - III : ASSERTION AND REASON TYPE 11. Statement -1 : The value of enthalpy of atomisation is generally maximum at about the middle of each series. Statement - 2 : There is one unpaired electron per d-orbital and this results in stronger interatomic interaction. (A) Statement - 1 is True, Statement-2 is True, Statemen-2 is a correct explanatio for Statement-1. (B) Statement-2 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1. (C) Statement-1 is True, Statement-2 is False (D) Statement-1 is False, Statement-2 is True 12. Statement-1 : To a solution of potassium chromate if a strong acid is added it changes its colour from yellow to organce. Statement - 2 : The colour change is due to hte oxidation of potassium chromate. (A) Statemen-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1. (C) Statement-1 is True, Statement-2 is False. (D) Statement-1 is False, Statement-2 is True 13. 14. Consider the following statements and arrange in the order of true/false as given in the codes. S1 : Interstitial compounds have high melting points, higher than thoses of pure metals. S2 : Permangnate titrations in presence of hydrochloric acid are unsatisfactory. S3 : KMnO4 does not act as an oxidising agent in strong alkaline medium. S4 : KMnO4 on heating in current of H2 gives MnO. (A) T T F T (B) T F F T (C) T F T T (D) F F T F S1 : Mn2+ compounds more stable than Fe2+ towards oxidation to their +3 state. S2 : Titanium and copper both in the first series of transition metals exhibits +1 oxidation state most frequently. S3 : Cu+ ion is stable in aqueous solutions. S4 : The E° value for the Mn3+/Mn2+ couple much more positive than that for Cr3+ / Cr2+ or Fe3+ / Fe2+ (A) T T F T (B) T F F T (C) T F T T (D) F F T F SECTION - IV : COMPREHENSION TYPE Read the following comprehensions carefully and answer the questions. Comprehension # 1 The (n–1) d shel of electrons in d-block elements is expanding and, therefore, they have many physical and chemical properties in common. They show variable oxidation state and all are metals. The transition elements i.e. d-block elements show an unparalled tendency to form coordination compounds with those groups whihc are able to donate an electron pair (i.e. lewis base). 15. Which oneis most acidic? (A) Cr2O3 (B) V2O5 (C) Mn2O7 (D) Fe2O3 TRANSITION ELEMENTS 16. Which of the following statement is incorrect? (A) Across a period from Sc toCu the densities increase with increasing atomic number (B) The melting point of transition elements rise to a maximum from Sc to Cr and then decreases from Fe to Zn. (C) Transition elements have high entahlpies of atomization and in 3d series increases regularly from Sc to Cu. (D) On going down a group from 3d to 6d series the stability of higher oxidation state increases with increasing atomic number. 17. Which of the following products are obtained when Na2CO3 is added to a solution of copper sulphate? (A) Basic coper carbonate [CuCO3Cu(OH)2], sodium sulphate and CO2. (B) Copper hydroxide, sodium sulphate and CO2. (C) Copper carbonate sodium sulphate and CO2. (D) Copper carbonate and sodium sulphate. Comprehension # 2 Paramagnetism is a property due to the presence of unpaired electrons. In case of transition metals, as they contain unpaired electrons in the (n – 1) d orbitals, most of the transition metal ions and their compounds are paramagnetic. Paramagnetism increases with increases in number of unpaired electrons. Magtnetic moment is calculated from ‘Spin only formula’ viz.   n(n  2) B.M. = n = no. of unpaired electrons Similarly the colour of the compounds of transitions metals may be attributed to the presence of incomplete (n –1) d subshell. When an electron froma lower energy of d-orbital is excited to a higher energy d-orbital, the energy of excitation corresponds to the frequency of light absorbed. This frequence generally lies in the visible region. The colour observed corresponds to complementary colour of the light absorbed. The frequency of the light absorbed is determined by the nature of the ligand. 18. Which of the following of compounds is expected to exhibit same colour in aqueous solution. (A) FeCl2, CuCl2 (B) VOCl2, CuCl2 (C) VOCl2, FeCl2 (D) FeCl2, MnCl2 19. Titanium shows magnetic moment of 1.73 BM in its compound. What is the oxidation state of titanium in the compound? (A) +2 (B) +1 (C) +3 (D) +4 20. Identify the incorrect statement. (A) Mn2+ has the highest paramagnetism amongst the bivalent cations of the Ist transition series. (B) The coloured ions or compounds of transition elements are due to d-d transition and charge transfer spectrum. (C) In 3 d series the paramagnetic character first increase to maximum & then starts decreasing (D) None of these Comprehension # 3 (I) A powdered substanced (A) on treatment with fusion gives a green coloured compound (B). (II) The solution of (B) in boiling water on acidification with dilute H2SO4 gives a pink coloured compound (C) (III) The aqueous solution of (A) on treatment iwth NaOH and Br2– water gives a compound (D). (IV) A solution of (D) in conc. HNO3 on treatment with lead peroxide at boiling temperature produced a compound (E) which was of the same colour at that of (C). (V) A solution of (A) on treatment iwht a solution of barium chloride gave a white precipitate of compound (F) which was insoluble in conc. HNO3 and conc. HCl. 21. Which of the following is true for compound (C). (A) It oxidises ammonia to nitrogen dioxide in neutral medium (B) It’s pink colour is due to d-d transition. (C) It can be oxidised by ozone. (D) It is obtained by alkaline fusion of pyrolusite in presence of air followed by electrolytic oxidation. 22. The oxidation state of centre metal ions of (A), (B) and (C) compounds are respectively : (A) + II, + VI and + VII (B) + II, + VI and + VI (C) + II, + VII and VII (D) + VI, + VII and + VII 23. Consider the following statements : (I) Anions of both (B) and (C) are diamagnetic and have tetradedral geometry. (II) Anions of both (B) and (C) are paramagnetic and have tetrahedral geometry. (III) Anions of (B) and (C) are paramagnetic and have tetrahedral geometry. (IV) Green coloured compound (B) in a neutral or acidic medium disproportionated to give (C) and (D). Of these select the correct one from the codes given : (A) I and III only (B) II and III only (C) II and IV only (D) III and IV only 24 Match the reactions in Column I with nature of the reactions/type of the products in Columns II. Column I Column II (A) MnO42– + H+  (p) One of the products of transition elementis paramagnetic (B) Cu+(aq)  (q) Disproportation reaction (C) Cr2O72–(s) + H+(conc.) + Cl–(s)  (r) One of the products is liberated as coloured vapours. (D) Fe2(SO4)3 + I–  (s) In one of the products central atom exhibits its highest oxidation state. 25 Match the reaction in Column I with type of the products/applications in Column II. Column I Column II SECTION - V : MATRIX - MATCH TYPE  (A) FeSO4   (B) Mn2+ + S2O82– + H2O  (C) Na2Cr2O7(saturated salt) + H2SO4 (conc.)  (D) N2H4 + CuSO4  26 (p) One of the product is coloured due to charge transfer (q) One of the product is in + VI oxidation state (r) Redox reaction (s) One of the product is acidic oxide Match the reaction in Column I with type of the products/applications in Column II. Column I Column II (A) HO OH (aq) + AgBr(s)  (p) Turnbull’s blue pigment (B) BaCl2 (s) + K2Cr2O7 (s) + H2SO4 (conc.)  (C) FeSO4 (aq) + K3[Fe(CN)6] (aq)  (D) Cu(OH)2 (s) + NH4OH (aq) + (NH4)2SO4 (s)  (q) Schwitzer’s reagent (r) Rinmann’s green pigment (s) Chromyl chloride test  (E) ZnO (s) + Co(NO3)2 (s)  (t) Photography SECTION - VI : SUBJECTIVE TYPE 27. Write two compounds in which compound does vanadium have an oxidation number of +4? 28. How many elements are present in each transition series? Why this number can not be less or more? 29. Why do transition element exhibit higher enthalpies of atomisation ? 30. The second and third member in each group of transition elements have similar atomic radii. Explain why? 31. E° for Mn+3 / Mn+2 is more positive then for Fe+3 / Fe+2. Account for this? MOCK - TEST 1. D 12. C 2. D 13. A 3. D 14. B 4. D 15. C 5. D 16. C 24. A  p, s ; B  r ; C  p, q ; D  p 26. A  t ; B  s ; C  p ; D  q ; E  r 6. A 17. A 7. A,B 18. B 8. 19. C A,B 9. A,B,D 20. D 21. D 25. A  q, r, s ; B - p, q, r ; C - p, q, s 4 - q, r 10. A,B,C,D 22. A 23. D 11. A