Terminology - Ligand, Coordination Number, Coordination Spher- UNSOLVED PRACTICE SET
Chapter: Coordination Compounds | Topic: Terminology Ligand Coordination Number Coordination Sphere
TERMINOLOGY - LIGAND, COORDINATION NUMBER, COORDINATION SPHER- UNSOLVED PRACTICE SET
Topic: Terminology Ligand Coordination Number Coordination Sphere
Multiple Choice Questions
Q1. The coordination number of a metal ion in a complex is determined by:
- The charge on the metal ion
- The number of ligand donor atoms directly bonded to the metal ion
- The total number of ligands in the complex
- The oxidation state of the metal only
Q2. Which of the following is a bidentate ligand?
- Cl⁻
- NH₃
- C₂O₄²⁻ (oxalate)
- H₂O
Q3. The coordination sphere of [Co(NH₃)₆]Cl₃ consists of:
- Only the Co³⁺ ion
- [Co(NH₃)₆]³⁺ and three Cl⁻ ions
- [Co(NH₃)₆]³⁺ only
- NH₃ molecules and Cl⁻ ions only
Q. Type your question here...
- Option A
- Option B
- Option C
- Option D
Q4. A ligand that can bind through two different donor atoms (but not simultaneously) is called:
- Bidentate ligand
- Ambidentate ligand
- Chelating ligand
- Polydentate ligand
Q5. The coordination number of Fe in [Fe(CN)₆]⁴⁻ is:
- 4
- 6
- 2
- 8
Short Answer Questions
Q7. Define the terms: (a) Ligand, (b) Coordination number, and (c) Coordination sphere. Give one example for each.
Q8. Distinguish between a monodentate and a bidentate ligand with suitable examples.
Q9. In the complex [Cr(H₂O)₆]Cl₃, identify the ligand, the coordination sphere, and the counterion. What is the coordination number of Cr?
Q10. What is meant by a chelating ligand? Why do chelating ligands form more stable complexes than monodentate ligands?
Q11. The complex [Ni(en)₃]²⁺ has a coordination number of 6, yet there are only 3 ligands. Explain how this is possible.
Q12. Identify the donor atoms in the following ligands: (a) SCN⁻, (b) NO₂⁻, (c) CO, and (d) H₂O.
Long Answer Questions
Q13. Explain the following terms with examples:
(a) Monodentate ligand
(b) Bidentate ligand
(c) Polydentate ligand
(d) Ambidentate ligand
(e) Chelating ligand
Q14. (a) Define coordination number. How is it different from the number of ligands in a complex?
(b) Determine the coordination number of the central metal ion in each of the following:
(i) [PtCl₆]²⁻
(ii) [Ag(NH₃)₂]⁺
(iii) [Fe(EDTA)]⁻
(iv) [Ni(CN)₄]²⁻
Q15. (a) What is a coordination sphere? Distinguish between the coordination sphere and the ionization sphere with examples.
(b) When the complex [Co(NH₃)₅Cl]Cl₂ is dissolved in water, how many chloride ions are precipitated immediately by AgNO₃ solution? Explain your answer.
Numerical / Application-Based Problems
Q16. A coordination compound has the formula PtCl₄·2NH₃. It does not conduct electricity in solution and does not give a precipitate with AgNO₃ solution.
(a) Write the possible structure of the complex.
(b) Identify the ligands, coordination number, and coordination sphere.
(c) Explain why no precipitate is formed with AgNO₃.
Q17. Consider the following complexes:
(i) [Co(NH₃)₆]Cl₃
(ii) [Co(NH₃)₅Cl]Cl₂
(iii) [Co(NH₃)₄Cl₂]Cl
(iv) [Co(NH₃)₃Cl₃]
For each complex:
(a) Identify the ligands and their types (monodentate/bidentate).
(b) Determine the coordination number of cobalt.
(c) Predict how many chloride ions would be precipitated immediately upon adding excess AgNO₃ solution.
(d) Identify the counter ions and the coordination sphere.
Q18. In your school chemistry lab, your teacher shows you three bottles labeled:
Bottle A: [Cr(H₂O)₆]Cl₃ (violet)
Bottle B: [Cr(H₂O)₅Cl]Cl₂·H₂O (light green)
Bottle C: [Cr(H₂O)₄Cl₂]Cl·2H₂O (dark green)
(a) Identify the ligands in each complex and determine the coordination number of chromium.
(b) When aqueous AgNO₃ is added to each solution, how many moles of AgCl will precipitate per mole of complex? Explain.
(c) These three compounds are examples of what type of isomerism? (Name the isomerism type only—do not explain.)
(d) Why do these complexes have different colours even though they contain the same metal ion?