Chemistry

Coordination Compounds

Question:

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+.

Answer:

[COF6]3-: Co3+ (d6)
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-23

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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.

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 3.

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

Q 4.

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 5.

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

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.

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

Q 8.

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 9.

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 10.

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

Q 11.

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

Q 12.

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

Q 13.

How many ions are produced from the complex Co(NH3)6Cl2 in solution?
(i) 6
(ii) 4
(iii)3
(iv)2

Q 14.

FeS04 solution mixed with (NH4)2SO4solution  in 1:1 molar ratio gives the test of,Fe2+ion but CuSO4solution mixed with aqueous ammonia in 1:4 molar ratio does not give the test of Cu2+ ion. Explain why.  

Q 15.

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 16.

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 17.

Why do compounds having similar geometry have different magnetic moment?

Q 18.

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 19.

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 20.

Why are low spin tetrahedral complexes not formed?

Q 21.

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

Q 22.

Assertion (A): (Fe(CN)6]3-  ion shows magnetic moment corresponding to two unpaired electrons.
Reason (R): Because it has d2sp3  type hybridisation.

Q 23.

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

Q 24.

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 25.

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

Q 26.

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.

Q 27.

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

Q 28.

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

Q 29.

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(H20)6]2+?

Q 30.

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 31.

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

Q 32.

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 33.

Using crystal field theory, draw energy level diagram, write electronic
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-38

Q 34.

Draw the structures of optical isomers of
(i) [Cr(C2O4)3]3-
(ii)[PtCI2(en)2]2+
(iii)[Cr(NH3)2CI2(en)]+

Q 35.

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

Q 36.

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 37.

Which of the following complex formed by Cu2+ ions is most stable?
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-1

Q 38.

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 39.

Match the complex ions given in Column I with the colours given in Column II and assign the correct code:
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-26

Q 40.

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 41.

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

Q 42.

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

Q 43.

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

Q 44.

How many geometrical isomers are possible in . the following coordination entities?
(i) [Cr(C2O4)3]3- (ii) [CoCl3(NH3)3]

Q 45.

Write all the geometrical isomers of [Pt(NH3)(Br)(Cl) (Py)] and how many of these will exhibit optical isomerism?

Q 46.

Aqueous copper sulphate solution (blue in colour) gives: (i) a green precipitate with aqueous potassium fluoride and  (ii)a bright green solution with aqueous potassium chloride. Explain these experimental results.

Q 47.

Using IUPAC norms write the systematic names of the following:
(i) [Co(NH3)6]CI3,
(ii)[Pt(NH3)2CI (NH2CH3)] Cl
(iii) [Ti(H20)6]3+
(iv) [Co(NH3)4Cl(N02)]CI
(v)|Mn(H20)6]2+
(vi)[NiCl4]2-
(vii)[Ni(NH3)6]CI2
(viii)[Co(en)3]3+
(ix) [Ni(CO)4]

Q 48.

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 49.

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

Q 50.

Explain why [Fe(H2O)6]3+  has magnetic moment value of 5.92 BM whereas [Fe(CN)6]3- has a value of only 1.74 BM.