Chemistry Class 12 NCERT Solutions: Chapter 9 Coordination Compounds Part 2

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Q: 4. What is meant by unidentate, didentate and ambidentate ligands? Give two examples for each.

Answer:

A ligand may contain one or more unshared pairs of electrons, which are called the donor sites of ligands. Now, depending on the number of these donor sites, ligands can be classified as follows:

(A) Unidentate ligands: Ligands with only one-donor sites are called unidentate ligands. For e.g. , etc.

(B) Didentate ligands: Ligands that have two donor sites are called didentate ligands. For e.g.,

(a) Ethane-1-2-diamine

(b) Oxalate ion

(C) Ambidentate Ligands:

Ligands that can attach themselves to the central metal atom through two different atoms are called ambidentate ligands. For example:

(a)

Q 4 (C) a 1 The Donor Atom is N

Q 4 (C) a 1 the Donor Atom Is N

Q 4 (C) a 1 The Donor Atom is N

Q 4 (C) a 2 The Donor Atom is Oxygen

Q 4 (C) a 2 the Donor Atom Is Oxygen

Q 4 (C) a 2 The Donor Atom is Oxygen

(b)

Q 4 (C) b 1 The Donor Atom is S

Q 4 (C) B 1 the Donor Atom Is S

Q 4 (C) b 1 The Donor Atom is S

Q 4 (C) b 2 The Donor Atom is N

Q 4 (C) B 2 the Donor Atom Is N

Q 4 (C) b 2 The Donor Atom is N

Q: 5. Specify the oxidation numbers of the metals in the following coordination entities:

(i)

(ii)

(iii)

(iv)

(v)

Answer:

Let the oxidation number of be .

The charge on the complex is

(ii)

Let the oxidation number of be

The charge on the complex is

(iii)

(iv)

(v)