Coordination Compounds is a Class 12 Chemistry chapter that carries about 4.5% of the Chemistry questions in NEET. Practise it with 48 questions covering 2 topics, each with an explanation.
Sample questions on Coordination Compounds with answers
8 questions from the practice bank, spread across the chapter's topics. The full set is in the app.
Question 1: Coordination Number and Oxidation State
The complex [Zn(NH₃)₄]²⁺ is colourless because:
- A Zn²⁺ has a d¹⁰ configuration, so no d–d transition is possible
- B the complex is ionic
- C ammonia absorbs all visible light
- D Zn²⁺ has no electrons
Answer: A. Zn²⁺ has a d¹⁰ configuration, so no d–d transition is possible
Why: A complete d subshell has no vacancy for an excited electron.
Question 2: Werner's Theory and Nomenclature
The coordination number of the central metal atom in a complex is the number of:
- A electrons in its outermost shell
- B ligand donor atoms directly bonded to the central atom
- C unpaired electrons it has
- D oxidation states it can show
Answer: B. ligand donor atoms directly bonded to the central atom
Why: Coordination number equals the number of ligand donor atoms directly bonded to the central metal ion, as defined in Werner's theory.
Question 3: Coordination Number and Oxidation State
The correct order of the strengths of ligands in the spectrochemical series is:
- A F⁻ < I⁻ < Cl⁻ < H₂O
- B CO < CN⁻ < NH₃ < H₂O < F⁻ < Cl⁻ < I⁻
- C I⁻ < Cl⁻ < F⁻ < H₂O < NH₃ < CN⁻ < CO
- D NH₃ < H₂O < CN⁻ < CO
Answer: C. I⁻ < Cl⁻ < F⁻ < H₂O < NH₃ < CN⁻ < CO
Why: Strong-field ligands cause a large splitting of the d orbitals.
Question 4: Werner's Theory and Nomenclature
[Co(NH₃)₅NO₂]²⁺ and [Co(NH₃)₅ONO]²⁺ are:
- A geometrical isomers
- B optical isomers
- C ionisation isomers
- D linkage isomers
Answer: D. linkage isomers
Why: The nitrite ion is bonded through N in one and through O in the other.
Question 5: Coordination Number and Oxidation State
The coordination number of cobalt in [Co(en)₃]³⁺ is:
- A 9
- B 3
- C 6
- D 4
Answer: C. 6
Why: Each ethylenediamine is bidentate, giving 3 × 2 = 6 donor atoms.
Question 6: Werner's Theory and Nomenclature
The tetrahedral complexes of the type [MA₂B₂] do not show:
- A optical isomerism of any kind
- B colour
- C magnetic properties
- D geometrical isomerism
Answer: D. geometrical isomerism
Why: All the positions in a tetrahedron are equivalent.
Question 7: Coordination Number and Oxidation State
The crystal field stabilisation energy of a low-spin d⁶ octahedral complex is:
- A −1.2Δo
- B −0.4Δo
- C −2.4Δo
- D zero
Answer: C. −2.4Δo
Why: Six electrons in t₂g: 6 × (−0.4Δo).
Question 8: Werner's Theory and Nomenclature
The number of ions produced when [Co(NH₃)₆]Cl₃ dissolves in water is:
- A 3
- B 6
- C 4
- D 9
Answer: C. 4
Why: It gives one complex ion [Co(NH₃)₆]³⁺ and three Cl⁻ ions.