9. COORDINATION COMPOUNDS

    1. Choose the most correct option.

    i. The oxidation state of cobalt ion in the complex [Co(NH3)5Br]SO4 is
    a. +2

    b. +3
    c. +1

    d. +4

    Solution

    ii. IUPAC name of the complex [Pt(en)2(SCN)2]2+ is
    a. bis (ethylenediamine dithiocyanatoplatinum (IV) ion
    b. bis (ethylenediamine) dithiocyantoplatinate (IV) ion
    c. dicyanatobis (ethylenediamine) platinate IV ion
    d. bis (ethylenediammine)dithiocynato platinate (IV) ion

    Solution

    iii. Formula for the compound sodium hexacynoferrate (III) is
    a. [NaFe(CN)6]

    b. Na2[Fe(CN)6]
    c. Na[Fe(CN)6]

    d. Na3[Fe(CN)6]

    Solution

    iv. Which of the following complexes exist as cis and trans isomers ?
    1. [Cr(NH3)2Cl4]

    2. [Co(NH3)5Br]2⊕

    3. [PtCl2Br2]2 (square planar)
    4. [FeCl2(NCS)2]2 (tetrahedral)
    a. 1 and 3

    b. 2 and 3
    c. 1 and 3

    d. 4 only

    Solution

    v. Which of the following complexes are chiral ?
    1. [Co(en)2Cl2]⊕

    2. [Pt(en)Cl2]
    3. [Cr(C2O4)3]3

    4. [Co(NH3)4Cl2]⊕
    a. 1 and 3

    b. 2 and 3
    c. 1 and 4

    d. 2 and 4

    Solution

    vi. On the basis of CFT predict the number of unpaired electrons in [CrF6]3 .
    a. 1

    b. 2

    c. 3

    d. 4

    Solution

    vii. When an excess of AgNO3 is added to the  complex one mole of AgCl is precipitated. The formula of the complex is
    a. [CoCl2(NH3)4]Cl
    b. [CoCl(NH3)4] Cl2

    c. [CoCl3(NH3)3]
    d. [Co(NH3)4]Cl3

    Solution

    viii. The sum of coordination number and  oxidation number of M in [M(en)2C2O4]Cl is
    a. 6

    b. 7

    c. 9

    d. 8

    Solution

    2. Answer the following in one or two entences.

    i. Write the formula for tetraammineplatinum (II) chloride.

    Solution

    ii. Predict whether the [Cr(en)2(H2O)2]3+ complex is chiral. Write structure of its
    enantiomer..

    Solution

    iv. Name the Lewis acids and bases in the complex [PtCl2(NH3)2].

    Solution

    v. What is the shape of a complex in which the coordination number of central metal
    ion is 4 ?

    Solution

    vi. Is the complex [CoF6] cationic or anionic if the oxidation state of cobalt ion is +3 ?

    Solution

    vii. Consider the complexes [Cu(NH3)4][PtCl4] and [Pt(NH3)4] [CuCl4]. What type of isomerism these two complexes exhibit?

    Solution

    viii. Mention two applications of coordination compounds.

    Solution

    3. Answer in brief.

    i. What are bidentate ligands ? Give one example.

    Solution

    ii. What is the coordination number and oxidation state of metal ion in the complex [Pt(NH3)Cl5] ?

    Solution

    iii. What is the difference between a double salt and a complex ? Give an example.

    Solution

    iv. Classify following complexes as homoleptic and heteroleptic [Cu(NH3)4]SO4, [Cu(en)2(H2O)Cl]2⊕, [Fe(H2O)5(NCS)]2⊕, tetraammine zinc (II) nitrate..

    Solution

    v. Write formulae of the following complexes a. Potassium amminetrichloroplatinate (II) b. Dicyanoaurate (I) ion

    Solution

    vi. What are ionization isomers ? Give an example.

    Solution

    vii. What are the high-spin and low-spin complexes ?

    Solution

    viii. [CoCl4]2 is tetrahedral complex. Draw its box orbital diagram. State which orbitals participate in hybridization.

    Solution

    ix. What are strong field and weak field ligands ? Give one example of each.

    Solution

    x. With the help of crystal field energylevel diagram explain why the complex [Cr(en)3]3⊕ is coloured ?

    Solution

    4. Answer the following questions.

    i. Give valence bond description for the bonding in the complex [VCl4] . Draw box diagrams for free metal ion. Which hybrid orbitals are used by the metal ?
    State the number of unpaired electrons.

    Solution

    ii. Draw qualitatively energy-level diagram showing d-orbital splitting in the octahedral environment. Predict the number of unpaired electrons in the complex [Fe(CN)6]4 . Is the complex diamagnetic or paramagnetic? Is it coloured? Explain.

    Solution

    iii. Draw isomers in each of the following
    a. [Pt(NH3)2ClNO2]
    b. [Ru(NH3)4Cl2]
    c. [Cr(en2)Br2]⊕

    Solution

    iv. Draw geometric isomers and enantiomers of the following complexes.
    a. [Pt(en)3]4⊕ b. [Pt(en)2ClBr]2⊕

    Solution

    v. What are ligands ? What are their types ? Give one example of each type

    Solution

    vi. What are cationic, anionic and neutral complexes? Give one example of each.

    Solution

    vii. How stability of the coordination compounds can be explained in terms of
    equilibrium constants ?

    Solution

    viii. Name the factors governing the equilibrium constants of the coordination compounds.

    Solution