1. What are coordination compounds?
Answer: Coordination compounds are molecules or ions composed of a central metal atom or ion bonded to ligands through coordinate covalent bonds.
2. Explain Werner’s theory of coordination compounds.
Answer: Werner’s theory proposed that coordination compounds contain a central metal atom or ion surrounded by ligands, and it introduced the concepts of coordination number, primary valence, and secondary valence.
3. Define ligands and coordination number in coordination compounds.
Answer: Ligands are molecules or ions that can donate electron pairs to form coordinate covalent bonds with a central metal atom or ion. Coordination number refers to the number of bonds formed between the central metal and its surrounding ligands.
4. What is denticity in coordination chemistry?
Answer: Denticity refers to the number of donor atoms in a ligand that can coordinate to a metal atom or ion. Ligands with multiple donor atoms can exhibit different denticities.
5. Explain chelation in coordination compounds.
Answer: Chelation occurs when a polydentate ligand forms multiple coordinate bonds with a central metal ion, typically forming a ring structure known as a chelate.
6. Discuss the IUPAC nomenclature of mononuclear coordination compounds.
Answer: The IUPAC nomenclature system for coordination compounds involves identifying the ligands, arranging them alphabetically, specifying the central metal atom, and indicating the oxidation state of the metal ion.
7. What is isomerism in coordination compounds?
Answer: Isomerism in coordination compounds refers to the existence of different compounds with the same molecular formula but different arrangements of atoms or ligands, leading to structural or stereochemical differences.
8. Explain the bonding in coordination compounds according to the valence bond approach.
Answer: The valence bond approach suggests that coordinate bonds in coordination compounds are formed by the overlap of atomic orbitals from the central metal atom/ion and the ligands, resulting in the sharing of electron pairs.
9. Discuss the basic ideas of Crystal Field Theory (CFT) in coordination chemistry.
Answer: Crystal Field Theory explains the electronic structure and properties of coordination compounds based on the interaction between the d-orbitals of the central metal ion and the ligand’s electric field.
10. Explain the color and magnetic properties of coordination compounds according to CFT.
Answer: The color of coordination compounds arises from the absorption of light due to the splitting of d-orbitals in the crystal field. Magnetic properties depend on the number of unpaired electrons resulting from this splitting.
11. What is the importance of coordination compounds in qualitative analysis?
Answer: Coordination compounds are used in qualitative analysis to selectively precipitate certain ions and separate them from the mixture, aiding in their identification.
12. Discuss the role of coordination compounds in the extraction of metals.
Answer: Coordination compounds are often used as intermediate compounds in the extraction of metals from ores due to their ability to stabilize metal ions in solution and facilitate separation processes.
13. How are coordination compounds important in biological systems?
Answer: Coordination compounds play essential roles in biological systems as metalloproteins, cofactors, and enzyme activators, participating in various biochemical processes such as oxygen transport and electron transfer.
14. Explain the concept of primary and secondary valence in Werner’s theory.
Answer: Primary valence represents the oxidation state or charge of the central metal ion, while secondary valence refers to the number of ligands that can bind to the metal ion.
15. Define stereochemistry in coordination compounds.
Answer: Stereochemistry refers to the spatial arrangement of atoms or groups around the central metal ion in coordination compounds, including geometric isomerism and optical isomerism.
16. Discuss the significance of geometric isomerism in coordination compounds.
Answer: Geometric isomerism occurs when different spatial arrangements of ligands around a central metal atom result in isomeric compounds with distinct physical and chemical properties, affecting reactivity and biological activity.
17. What is optical isomerism, and how does it arise in coordination compounds?
Answer: Optical isomerism occurs when coordination compounds have non-superimposable mirror images (enantiomers). It arises when the complex lacks an internal plane of symmetry, resulting in chiral compounds.
18. Explain the concept of coordination sphere and its components.
Answer: The coordination sphere of a coordination compound includes the central metal ion and the ligands directly bonded to it. It does not include any counterions or solvent molecules.
19. Discuss the role of coordination compounds in catalysis.
Answer: Coordination compounds serve as catalysts in various chemical reactions, facilitating bond formation or cleavage by providing an alternative reaction pathway with lower activation energy.
20. How do coordination compounds exhibit variable oxidation states?
Answer: Coordination compounds can exhibit variable oxidation states due to the ability of the central metal ion to donate or accept electrons during bonding with ligands, resulting in different charge states for the metal ion.