Chemistry

Coordination Compounds

Question:

Write the IUPAC names of the following coordination compounds:
(i)[Co(NH3)6]Cl3
(ii)[Co(NH3)5Cl]Cl2
(iii)K3[Fe(CN)6l
(iv)K3lFe(C2O4)3]
(v)K2[PdCl4]
(vi)[Pt(NH3)2Cl(NH2CH3)]Cl

Answer:

(i) Hexaamminecobalt (III) chloride
(ii)Pentaamminechloridecobalt (III) chloride
(iii)Potassium hexacyanoferrate (III)
(iv)P9tassiumtrioxalatoferrate(III)
(v)Potassium tetrachloridopalladate (II)
(vi)Diamminechloride (methylamine) platinum (II) chloride

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Coordination Compounds

Q 1.

When 1 mol CrCl3.6H2O is treated with excess of AgNO3, 3 mol of AgCl are obtained. The formula of the complex is
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-6

Q 2.

What is meant by unidentate didentate and ambidentate ligands? Give two examples for each.

Q 3.

Assertion (A): [Cr(H2O)6]Cl2 and [Fe(H2O)6]Cl2 are reducing in nature. Reason (R): Unpaired electrons are present in their J-orbitals.

Q 4.

Write the IUPAC names of the following coordination compounds:
(i)[Co(NH3)6]Cl3
(ii)[Co(NH3)5Cl]Cl2
(iii)K3[Fe(CN)6l
(iv)K3lFe(C2O4)3]
(v)K2[PdCl4]
(vi)[Pt(NH3)2Cl(NH2CH3)]Cl

Q 5.

Calculate the overall complex dissociation equilibrium constant for the  Cu(NH3)42+  ion, given that β4  for this complex is 2.1 x  1013.

Q 6.

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.

Q 7.

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.

Q 8.

Magnetic moment of [MnCl4]2- is 5.92 BM. Explain giving reason.

Q 9.

The colour of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of wavelength of
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-3

Q 10.

Arrange following complex ions in increasing order of crystal field splitting energy (A0):
[Cr(Cl)6]3-, [Cr(CN)6]3-, [Cr(NH3)6]3+

Q 11.

Amongst the following, the most stable complex is:
(i) [Fe(H2O)6] (ii) [Fe(NH3)6]3+
(iii) [Fe(C2O4)3]3- (iv) [FeCl6]3-

Q 12.

Which of the following options are correct for [Fe(CN)6]3- complex?
(a) d2sp3 hybridisation
(b) sp3d2  hybridisation
(c) Paramagnetic
(d) Diamagnetic

Q 13.

CUSO4.5H2O is blue in colour while CuSO4 is colourless. Why?

Q 14.

[Fe(CN)6]4- and [Fe(H2O)6]2+ are of different cdlours in dilute solutions. Why?

Q 15.

What is meant by the chelate effect? Give an example.

Q 16.

Indicate the complex ion which shows geometrical isomerism.
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-8

Q 17.

The CFSE for octahedral [COCl6]4- is 18,000 cm-1. The CFSE for tetrahedral [COCl4]2- will be
(a) 18,000 cm-1(b) 16,000 cm-1 (c) 8,000 cm-1 (d) 20,000 cm-1

Q 18.

Match the complex species given in Column I with the possible isomerism given in Column II and assign the correct code:
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-32

Q 19.

Assertion (A): Linkage isomerism arises in coordination compounds containing ambidentate ligand.
Reason (R): Ambidentate ligand has two different donor atoms.

Q 20.

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

Q 21.

Arrange the following complexes in the increasing order of conductivity of their solution:
[Co(NH3)3Cl3], [CO(NH3)4Cl2]Cl, [CO(NH3)6]C13, [Cr(NH3)5Cl]Cl2

Q 22.

In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the following choices.
(a) Assertion and Reason both are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason both are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true, Reason is false.
(d) Assertion is false, Reason is true.

Assertion (A): Toxic metal ions are removed by the chelating ligands. Reason (R): Chelate complexes tend to be more stable.

Q 23.

Discuss the nature of bonding in metal carbonyls.

Q 24.

Which of the following complexes show linkage isomerism?
(a) [CO(NH3)5(NO2)]2+  (b) [CO(H2O)5CO]3+
(c) [Cr(NH3)5SCN]2+  (d) [Fe(en)2Cl2]+

Q 25.

Why are low spin tetrahedral complexes not formed?

Q 26.

Name the type of isomerism when ambidentate ligands are attached to central metal ion. Give two examples of ambidentate ligands.

Q 27.

Match the coordination compounds given in Column I with the central metal atoms given in Column II and assign the correct code:
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-27
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-28

Q 28.

The hexaquomanganese(II) ion contains five unpaired electrons, while the hexacyano ion contains only one unpaired electron. Explain using Crystal Field Theory.

Q 29.

What is crystal field splitting energy? How does the magnitude of Δ0 decide the actual configuration of d-orbitals in a coordination entity?

Q 30.

Which of the following complexes are homoleptic?
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-16

Q 31.

Why do compounds having similar geometry have different magnetic moment?

Q 32.

Assertion (A): Complexes of MX6 and MX5L type (X and L are unidentate) do not show geometrical isomerism.
Reason (R): Geometrical isomerism is not shown by complexes of coordination number 6.

Q 33.

What is the relationship between observed colour of the complex and the wavelength of light absorbed by the complex?

Q 34.

Why are different colours observed in octahedral and tetrahedral complexes for the same metal and same ligands?

Q 35.

Using IUPAC norms write the formulas for the following:
(i)Tetrahydroxozincate(Il)
(ii)Potassium tetrachloridopalladate (II)
(iii)Diamminedichlorido platinum (II)
(iv)Potassium tetracyanonickelate (II)
(v)Pentaamminenitrito-O-cobalt(III)
(vi)Ilexaamminccobalt (III) sulphate
(vii)Potassium tri(oxalato) chromate (III)
(yiii)Hexaammineplatinum (IV)
(ix)Tetrabromidocuprate(II)
(x) Pentaamminenitrito-N-cobalt (III)

Q 36.

What is the coordination entity formed when excess of aqueons KCN is added to an aqueous solution of copper sulphate? Why is it that no precipitate of copper sulphide is obtained when H2S (g) is passed through this solution?

Q 37.

Discuss briefly giving an example in each case the role of coordination compounds in:(i)biological systems (iii) analytical chemistry (ii)medicinal chemistry and (iv) extraction/ metallurgy of metals.

Q 38.

Amongst the following ions? Which one has the highest magnetic moment value:
(i) [Cr(H2O)6]3+
(ii) [Fe(H20)6]2+ (iii) [Zn(H20)6]2+

Q 39.

The stabilization of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-7

Q 40.

An aqueous pink solution of cobalt (II).chloride changes to deep biue on addition of excess of HCl. This is because
(a) [Co(H2O)6]2+ is transformed into [CoCl6]4-
(b) [CO(H2O)6]2+ is transformed into [COCl4]2-
(c) tetrahedral complexes have smaller crystal field splitting than octahedral complexes
(d) tetrahedral complexes have larger crystal field splitting than octahedral complex

Q 41.

Give evidence that  [Co(NH3)5Cl]S04  and [Co(NH3)5S04]Cl  are ionisation isomers.

Q 42.

Explain on the basis of valence bond theory that  [Ni(CN)4]2-  ion with square planar structure is diamagnetic and the[Ni(CN)4]2- ion with tetrahedral geometry is paramagnetic.

Q 43.

Explain with two examples each of the following: coordination entity, ligand, coordination number, coordination polyhedron, homoleptic and heteroleptic.

Q 44.

Identify the optically active compounds from the following:
(a) [Co(en)3]3+  (b) trans-[Co(en)2Cl2]+
(c) cis-[Co(en)2Cl2]+ (d) [Cr(NH3)5Cl]

Q 45.

Identify the correct statements for the behaviour of ethane-1, 2-diamine as a ligand.
(a) It is a neutral ligand (b) It is a didentate ligand
(c) It is a chelating ligand (d) It is a unidentate ligand

Q 46.

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+.

Q 47.

[Fe(H2O)6]3+is strongly paramagnetic whereas  [Fe(CN)6]3-is weakly paramagnetic. Explain.

Q 48.

Explain the bonding in coordination compounds in terms of Werner's postulates.

Q 49.

Draw all the isomers (geometrical and optical) of
(i)[CoCl2(en)2]+
(ii)[Co(NH3) Cl (en)2]2+
(iii) [Co(NH3)2Cl2(en)]+

Q 50.

Draw figure to show the splitting of d-orbitals in an octahedral crystal field.