Co-ordination Compound- Questions

Short Answer Type Questions

  1.  Arrange the following complexes in the increasing order of conductivity of their solution: [Co(NH3)3Cl3], [Co(NH3)4Cl2]Cl, [Co(NH3)6]Cl3, [Cr(NH3)5Cl]Cl2
  2. A coordination compound

    CrCl3⋅4H2O precipitates silver chloride when treated with silver nitrate. The molar conductance of its solution corresponds to a total of two ions. Write structural formula of the compound and name it.

  3. A complex of the type [M(AA)2X2]n+ is known to be optically active. What does this indicate about the structure of the complex?

    Give one example of such complex.

  4. Magnetic moment of [MnCl4]2– is 5.92 BM. Explain giving reason.
  5. On the basis of crystal field theory explain why Co(III) forms paramagnetic octahedral complex with weak field ligands whereas it forms diamagnetic octahedral complex with strong field ligands.
  6. Why are low spin tetrahedral complexes not formed?
  7. Give the electronic configuration of the following complexes on the basis of Crystal Field Splitting theory.
    [CoF6]3- , [Fe(CN)6]4- and [Cu(NH3)6]2+.
  8. Explain why [Fe(HO)6]3+ has magnetic moment value of 5.92 BM whereas
    [Fe(CN)6]3- has a value of only 1.74 BM.
  9. Arrange following complex ions in increasing order of crystal field splitting energy (ΔO):
    [Cr(Cl)6]3– , [Cr(CN)6]3–,[Cr(NH3)6]3+.
  10. Why do compounds having similar geometry have different magnetic moment?
  11. CuSO4.5H2O is blue in colour while CuSO4 is colourless. Why?
  12. Name the type of isomerism when ambidentate ligands are attached to central metal ion. Give two examples of ambidentate ligands.

Assertion and Reason Type Questions

Note : In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(i) Assertion and reason both are true, reason is correct explanation of  assertion.
(ii) Assertion and reason both are true but reason is not the correct  explanation of assertion.
(iii) Assertion is true, reason is false.
(iv) Assertion is false, reason is true.

  1. Assertion : Toxic metal ions are removed by the chelating ligands.
    Reason : Chelate complexes tend to be more stable.
  2. Assertion :[Cr(H2O)6]Cl2 and [Fe(H2O)6]Cl2 are reducing in nature.
    Reason : Unpaired electrons are present in their d-orbitals.
  3. Assertion : Linkage isomerism arises in coordination compounds containing ambidentate ligand.
    Reason : Ambidentate ligand has two different donor atoms.
  4. Assertion : Complexes of MX6 and MX5 L type (X and L are unidentate) do not show geometrical isomerism.
    Reason: Geometrical isomerism is not shown by complexes of coordination number
  5. Assertion : ([Fe(CN)6]3- ion shows magnetic moment corresponding to two unpaired electrons.
    Reason : Because it has d2sp3 type hybridisation.

Long Answer Type Questions

  1. Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following :
    (i) [CoF6]3– ,[Co(H2O)6]2+, [Co(CN)6]3–
    [FeF6]3– , [Fe(H2O)6]2+ , [Fe(CN)6]4–
  2. Using valence bond theory, explain the following in relation to the complexes given below:
    [Mn(CN) 6 ]3– , [Co(NH3)6]3+ , [Cr(H2O)6]3+ , [FeCl6]4–
    (i) Type of hybridisation.
    (ii) Inner or outer orbital complex.
    (iii) Magnetic behaviour.
    (iv) Spin only magnetic moment value.
  3. CoSO4 Cl.5NH3

    exists in two isomeric forms ‘A’ and ‘B’. Isomer ‘A’ reacts with AgNO 3 to give white precipitate, but does not react with BaCl2. Isomer ‘B’ gives white precipitate with BaCl2 but does not react with AgNO3 . Answer the following questions.
    (i) Identify ‘A’ and ‘B’ and write their structural formulas.
    (ii) Name the type of isomerism involved.
    (iii) Give the IUPAC name of ‘A’ and ‘B’.

  4. What is the relationship between observed colour of the complex and the wavelength of light absorbed by the complex?
  5. Why are different colours observed in octahedral and tetrahedral complexes for the same metal and same ligands?

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