Sample Questions of Coordination chemistry

Sample Questions of Coordination chemistry: 1 marker

Very short answer type questions (1 mark):

Q1. Write the formula of Dichloridobis(ethane-1,2-diamine)cobalt(III).

Q2. Write the IUPAC name of [Pt(NH3)2Cl(NH2CH3)]Cl.

Q3. The spin only magnetic moment of [MnBr4]2- is 5.9 BM. Predict the geometry of the complex ion?

Q4. Predict the number of unpaired electrons in the square planar [Pt(CN)4]2-

Q5. Calculate the overall complex dissociation equilibrium constant for the [Cu(NH3)4]2+ion, given that β4 for this complex is 2.1 x 1013

Sample Questions of Coordination chemistry: 2 marker

Short answer type questions (2 marks):

Q1. Give reason for the following.

(i)[NiCl4]2- is paramagnetic while [Ni(CO)4] is diamagnetic though both are tetrahedral.

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

Q2. (i)Explain [Co(NH3)6]3+ is an inner orbital complex whereas [Ni(NH3)6]2+ is an outer orbital complex.

(ii)The hexaaquamanganese (II) ion contains five unpaired electrons while the hexacyanoion contains only one unpaired electron. Explain using crystal field theory.

Q3. (i)Using IUPAC norms, write the formula of Pentaamminenitrito-N-cobalt(III)chloride.

(ii)Write the IUPAC name of [Co(NH3)4Cl(NO2)]Cl

Q4. (i)Which of the following is more stable complex and why?

[Co(NH3)6]3+  and [Co(en)3]3+

(ii) What do you understand by ‘denticity of a ligand’? What is the denticity of EDTA?

Q5. (i)Explain the following:

[Fe(CN)6]4- and [Fe(H₂O)6], are of different colours in dilute solutions.

(ii)Arrange the following complex ions in increasing order of crystal field splitting energy (0)

[Cr(Cl) 6 ]3- , [Cr(CN) 6 ] 3- , [Cr(NH3 )6 ]3-

Q6. (i)Give an example of Homoleptic and heteroleptic complex.

(ii)What is pairing energy?

Q7. When a coordination compound CrCl3. 6NH3 is mixed with AgNO3, 2 moles of AgCl are precipitated per mole of the compound. Write

(i)Structural formula of the complex.

(ii)IUPAC name of the complex.

Q8. (i)Write down the IUPAC name of [Cr(NH3)₂Cl₂(en)₂]Cl

(ii)Write the formula for Pentaamminenitrito-o-cobalt (III)chloride.

Also check: CBSE Class 12 Chemical Kinetics MCQs

Sample Questions of Coordination chemistry: 3 markers

Short answer type questions (3 marks):

Q1.(a) How is a double salt different from a complex?

(b)Write IUPAC names of the following:

(i)K3 [Fe(C2O4) 3]   (ii)[Pt(NH3)6 ]Cl4

Q2. (a)Explain why [Co(NH3 )6]3+ is an inner orbital complex whereas [ Ni(NH3)6] an outer  orbitals complex.

(b)State reason for each of the following:

(i) CO is stronger complexing reagent than NH3.

(ii) molecular shape of Ni(CO)4 is not the same as that of [Ni(CN)4] 2-

Q3. Explain the following:

(i)Low spin octahedral complexes of nickel are not known.

(ii)The π- complexes are known for transition elements.

(iii)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(H2O)6]2+

Q4. Draw figures to show the splitting of d orbitals in an octahedral crystal field.

Q5. What is spectrochemical series? Explain the difference between a weak field ligand and a strong field ligand.

Q6. What is crystal field splitting energy? How does the magnitude of ∆o decide the actual configuration of d orbitals in a co-ordination entity?

Q7. (a)What is meant by chelate effect? Give an example.

(b)Discuss the nature of bonding in metal carbonyls.

Q8. (a) A coordination compound with the molecular formula CrCl3.4H2O precipitates AgCl with AgNO3 solution. Its molecular conductivity is found to be equivalent to two ions. What is the structural formula and IUPAC name of the compound?

(b)Which of the following is more stable complex and why? [Co(NH3)6]3+ and [Co(en)3]3+

Q9. (a) Write the electronic configuration of Fe(III) on the basis of crystal field theory when it forms an octahedral complex in the presence of (i)strong field ligand (ii)weak field ligand.

(b)Why are low spin tetrahedral complexes not formed?

Q10. A chloride of fourth group cation in qualitative analysis gives a green coloured complex [A] in aqueous solution which when treated with ethane-1,2-diamine (en) gives pale yellow solution [B]which on subsequent addition of ethane-1,2-diamine (en) turns to blue or purple solution [C] and finally to violet [D]. Write the structures of complexes [A], [B], [C] and [D].

Q11. Write the hybridisation type, magnetic character and spin nature of the following complexes. (i) [Fe(CN)6]3- (ii) [Fe(CO)5]

Q12. A metal ion Mn+ having d4 valence electronic configuration combines with three bidentate ligands to form a complex compound. Assuming ∆o> P,

(i)Orbital splitting during this complex formation.

(ii)What type of hybridisation will Mn+ ion have?

(iii)Write the electronic configuration of Mn+ ion in terms of t2g and eg

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Sample Questions of Coordination chemistry: 5 marker

Long answer type questions: Based on case study (5 marks):

Coordination compounds are the compounds in which the central metal atom is linked to a number of ions or neutral molecules by co-ordinate bonds and the donor atoms. Molecules or ions which donate a pair of electrons to the metal atom or ion and form a co-ordinate bond with it are called ligands. Coordination number is the number of atoms or ions immediately surrounding a central atom in a complex or a crystal.

Coordination number of Ni2+ is 4 and it forms two complexes A and B as given below.

NiCl2 + KCN → A (Cyano complex)

NiCl2 + HCl → B (Chloro complex)

(i)Write the IUPAC name of complex A.

(ii)Write the formula of complex B.

(iii)Predict the magnetic nature of A.

(iv)Write the state of hybridisation of the complex B.

(v)What will be the shape of the complex A?

Also Check: CBSE Class 12 Electrochemistry MCQs