Chemistry

Coordination Compounds

Question:

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

Answer:

ncert-exemplar-problems-class-12-chemistry-coordination-compounds-25

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Coordination Compounds

Q 1.

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 2.

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 3.

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 4.

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

Q 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.

Q 6.

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 7.

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

Q 8.

The oxidation number of cobalt in K[Co(CO)4] is
(i)+1
(ii)+3
(iii)-1
(iv)-3

Q 9.

Why are low spin tetrahedral complexes not formed?

Q 10.

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

Q 11.

CoSO4Cl.5NH3 exists in two isomeric forms ‘A' and ‘B'. Isomer ‘A' reacts with AgNO3 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'.

Q 12.

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 13.

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 14.

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 15.

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 16.

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

Q 17.

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 18.

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

Q 19.

Atomic number of Mn, Fe, Co and Ni are 25, 26 27 and 28 respectively. Which of the following outer orbital octahedral complexes have same number of unpaired electrons?
(a) [MnCl6]3- (b) [FeF6]3- (c) [CoF6]3- (d) [Ni(NH3)6]2+

Q 20.

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

Q 21.

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 22.

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 23.

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

Q 24.

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

Q 25.

Which of the following complexes are heteroleptic?
ncert-exemplar-problems-class-12-chemistry-coordination-compounds-17

Q 26.

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

Q 27.

Discuss the nature of bonding in metal carbonyls.

Q 28.

CoSO4Cl.5NH3 exists in two isomeric forms ‘A' and ‘B'. Isomer ‘A' reacts with AgNO3 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'.

Q 29.

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 30.

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

Q 31.

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 32.

Why do compounds having similar geometry have different magnetic moment?

Q 33.

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 34.

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

Q 35.

Write the formulas for the following coordination compounds:
(i)Tetraamminediaquacobalt(IlI) chloride
(ii)Potassium tetracyanidonickelate(II)
(iii)Tris(ethanp-1,2-diamine) chromium(III) chloride
(iv)Amminebromidochloridonitrito-N- platinatc(II)
(v)Dichloridobis(ethane-l ,2-diamine) platinum (IV) nitrate
(vi)Iron(III)hexacyanidoferrate(II)

Q 36.

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

Q 37.

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

Q 38.

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 39.

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

Q 40.

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 41.

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

Q 42.

Give the oxidation state, d-orbital occupation and coordination number of the central metal ion in the following complexes:
(i)K3[CO(C2O4)3I (ii) cis-[Cr(en)2Cl2]Cl (iii) (NH4)2[CoF4] (iv) [Mn(H20)6]SO4

Q 43.

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

Q 44.

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 45.

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 46.

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 47.

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 48.

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

Q 49.

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 50.

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