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Important Questions

CBSE Guess > Papers > Important Questions > Class XII > 2009 > Chemistry > Chemistry By Mr. Mahendra Kalra


Q. 1. (a) What is a Difference between a double salt and a complex.

(b). Explain the following with suitable examples: Homoleptic and Heteroleptic ligands, Coordination number.

Q. 2. What is meant by unidentate, didentate and ambidentate ligands? Give examples for each.

Q. 3. (a)Specify the oxidation numbers of the metals in the following coordination entities

  1. [Co(H2O)(CN)(en)2]2+
  2. [PtCl4]2–
  3. [Cr(NH 3)3Cl3]
  4. [CoBr2(en)2]+
  5. K3[Fe(CN)6]

Q. 4. (a) Using IUPAC norms write the formulae for the following:

  1. Tetrahydroxozincate(II) ion
  2. pentaamminenitrito-N-cobalt (III)
  3. Potassiumtri(oxalato) chromate (III)
  4. Diamminedichloridoplatinum (II)
  5. Hexaammine cobalt (III) sulphate
  6. Potassiumtetrachloridopalladate (II)
  7. Hexaammineplatinum (IV)
  8. potassiumtetracyanonickelate (II)
  9. Tetrabromido cuprate (II)
  10. pentaamminenitrito-O-cobalt (III)
  11. Tetraammineaquachloridocobalt (III) chloride
  12. Potassiumtetrahydroxozincate (II)
  13. Potassiumtrioxalatoaluminate (III)
  14. Dichloride bis (ethane-1, 2-diamine) cobalt (III)
  15. Tetracarbonylnickel (0)

(b) Write the formulas for the following coordination compounds:

  1. Tetraamminediaquacobalt(III) chloride
  2. Potassium tetracyanonickelate(II)
  3. Tris(ethane–1, 2–diamine) chromium(III) chloride
  4. Amminebromidochloridonitrito-N-platinate(II)
  5. Dichloridobis(ethane–1, 2–diamine)platinum(IV) nitrate
  6. Iron(III) hexacyanoferrate(II)

Q. 5. (a) Write the IUPAC names of the following coordination compounds:

  1. [Pt (NH3)4Cl(NO2)]+
  2. K3[Cr (C2O4)3]
  3. [CoCl2 (en) 2]Cl
  4. [Co (NH3)5(CO3)]Cl
  5. Hg [Co (SCN)4]
  6. [Co (NH3)6)]Cl3
  7. [Co (NH3)5Cl]Cl2
  8. K3 [Fe (CN) 6]
  9. K3 [Fe (C2O4)3]
  10. K2 [PdCl4]
  11. [Pt (NH3)2Cl (NH2CH3)]Cl
  12. [NiCl4]2-
  13. [Ni (CO) 4]
  14. [Co (en) 3]3+
  15. [Co (NH3)6] Cl3
  16. [Co (NH3)4Cl (NO2)]Cl
  17. [Ni (NH3)6]Cl2
  18. [Mn (H2O)6]+
  19. [Co (en) 3]3+
  20. [Ti(H2O)6]3+

(b) Write the IUPAC names of the following coordination compounds:

  1. [Co(NH3)6]Cl3
  2. [Co(NH3)5Cl]Cl2
  3. K3[Fe(CN)6]
  4. K3[Fe(C2O4)3]
  5. K2[PdCl4]
  6. [Pt(NH3)2Cl(NH2CH3)]Cl

Q. 6. The oxidation number of cobalt in K[Co(CO)4] is

  1. +1
  2. +3
  3. -1
  4. -3

Q. 7. What is understood by following, explain giving examples:

  1. Linkage Isomerism
  2. Ionization isomerism
  3. Coordination isomerism
  4. Solvate(Hydrate)isomerism

Q. 7. What is understood by geometrical and optical isomers?

Q. 8. Draw all the structures of optical isomers of

  1. [CrCl(en)2(NH3)]2+
  2. [CrCl2(en)2]+
  3. [Cr(C2O4)3]3-
  4. [PtCl 2(en)2]+
  5. [CrCl2 (en) (NH3)2]2+
  6. [CoCl (en) 2(NH3)] 2+
  7. K[Cr (H2O) 2(C2O4)2]
  8. [Co(en)3]Cl3

Q. 9. Draw all the structures of geometrical isomers of:

  1. [Pt(NH3)2Cl2]
  2. [ Co(NH3)4Cl2]+
  3. [ CrCl(en)2(NH3)]2+
  4. [ CrCl2 (en) 2] +
  5. [ Pt (NH3) (H2O) Cl2]
  6. [ CoCl (en) 2(NH3)] 2+
  7. [ CrCl2 (en)(NH3)2]2+

Q. 10. Write all the geometrical isomers of [Pt(NH3)(Br)(Cl)(py)] and how many of these will exhibit optical isomers?

Q. 11. Why is geometrical isomerism not possible in tetrahedral complexes having two different types of unidentate ligands coordinated with the central metal ion ?

Q. 12. Draw structures of geometrical isomers of [Fe(NH3)2(CN)4]

Q. 13. Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers:

  1. K[Cr(H2O)2(C2O4)2
  2. [Co(en)3]Cl3
  3. [Co(NH3)5(NO2)](NO3)2
  4. [Pt(NH3)(H2O)Cl2]

Q. 14. Give evidence that [Co(NH3)5Cl] SO4 and [Co(NH3)5SO4]Cl are ionization isomers.

Q. 15. Using VBT Predict the Magnetic behaviour, Hybridization, Shape of following

  1. [ Fe (CN)6]4-
  2. [ Fe F6]3-
  3. [ Co F6]3-
  4. [ Co(C2O4)3]3-
  5. [ Ni(CN)4]2-
  6. [ NiCl4]2-
  7. [ Ni (CO)4]
  8. [ Fe (H2O) 6]3+
  9. [ Fe (CN)6]3-
  10. [ Co (NH3)6] +3
  11. [ Ni (NH3)6] +2
  12. [ Ti(H2O)6]3+

Q. 16. Account for the Following:

  1. [ Ni (CN)4]2- ion with square planar structure is diamagnetic and the [ NiCl4]2- ion with tetrahedral structure is paramagnetic .
  2. [ NiCl4]2- is paramagnetic while [ Ni (CO)4] is diamagnetic though both are tetrahedral.
  3. [ Fe (H2O) 6]3+is strongly paramagnetic while [Fe(CN)6]3- is weakly paramagnetic.
  4. [ Co (NH3)6]+3 is an inner orbital complex whereas [Ni(NH3)6]+2 is an outer complex.
  5. [ Cr (NH3)6] +3is paramagnetic while [Ni (CN)4]2- is diamagnetic.
  6. A solution of [Ni (H2O) 6]2+ is green but a solution of [Ni (CN)4]2- is colourless.
  7. [ Fe (CN)6]3- and [Fe(H2O) 6]3+ are of different colours in dilute solutions.

Q. 17. The spin only magnetic moment of [MnBr4]2– is 5.9 BM. Predict the geometry of the complex ion.

Q. 18. 4. Predict the number of unpaired electrons in the square planar [Pt(CN)4]2– ion.

Q. 19. Draw diagram to show splitting of d – orbital in octahedral crystal field. Explain the two patterns of filling d4 in octahedral crystal Field.

Q. 20. Draw diagram to show splitting of d – orbital in a tetrahedral crystal field.

Q. 21. The Hexaaquomanganese (II) ion contains five unpaired electrons, while the Hexacyano manganese (II) ion contains only one unpaired electron. Explain using CFT.

Q. 22. (a)Write down the IUPAC name for each of the following complexes and indicate the oxidation state, electronic configuration and coordination number. Also give stereochemistry and magnetic moment of the complex:

  1. K[Cr(H2O)2(C2O4)2]3H2O
  2. [CrCl3(py)3] (v) K4[Mn(CN)6]
  3. [Co(NH3)5Cl]Cl2
  4. Cs[FeCl4]

(b) Give the oxidation state, d orbital occupation and coordination number of the central metal ion in the following complexes:

  1. K3[Co(C2O4)3]
  2. (NH4)2[CoF4]
  3. cis-[Cr(en)2Cl2]Cl
  4. [Mn(H2O)6]SO4

Q. 23. Explain the bonding in coordination compounds in terms of Werner’s postulates

Q. 24. Discuss the role of coordination chemistry in

  1. Biological systems
  2. Analytical Chemistry
  3. Medicinal Chemistry
  4. metallurgy / Extraction of metals

Q. 25. What is the coordination entity formed when excess of aqueous KCN is added to an aqueous solution of Copper sulphate? Why is it that no precipitates of Copper sulphide is obtained when H2S (g) is passed through this solution.

Q. 26. What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.

Q. 27. What is crystal field splitting energy? How does the magnitude of ∆0 decide the actual configuration of d-orbital in a coordination entity?

Q. 28. What is meant by stability of a coordination compound in solution? State the factors which govern stability of complexes.

Q. 29. What is meant the chelate effect? Give an example.

Q. 30. Discuss the nature of Bonding in metal carbonyls.

Q. 31. Multiple choice questions

(a). How many ions are produced from the complex Co(NH3)6Cl2 in solution?

  1. 6
  2. 4
  3. 3
  4. 2

(b). Amongst the following ions which one has the highest magnetic moment value?

  1. [Cr(H2O)6]3+
  2. [Fe(H2O)6]2+
  3. [Zn(H2O)6]2+

(c). Amongst the following, the most stable complex is

  1. [Fe(H2O)6]3+
  2. [Fe(NH3)6]3+
  3. [Fe(C2O4)3]3–
  4. [FeCl6]3–

Q. 32. What will be the correct order for the wavelengths of absorption in the visible region for the following: [Ni(NO2)6]4–, [Ni(NH3)6]2+, [Ni(H2O)6]2+ ?

Paper By Mr. Mahendra Kalra