Ch 5Coordination Compounds — Class 12 Chemistry, concept-first.

The previous unit on the d- and f-block elements established that transition metals readily form a large number of complex compounds, in which a metal atom or ion is bound to a set of surrounding anio…

Transition metals readily bind to a number of anions or neutral molecules through shared electron pairs, producing what are now called coordination compounds.

At the heart of coordination chemistry is the coordination entity: a central metal atom or ion held together with a fixed set of surrounding ions or molecules.

A coordination compound can often be built up from a metal and a chosen set of ligands in more than one arrangement, and different arrangements — the isomers you will meet in the next section — can be…

A formula is a compact way of stating what a compound is made of. For a mononuclear coordination entity — one built around a single central metal atom or ion — the formula is assembled by following a…

Naming a coordination compound follows the principles of additive nomenclature: every group attached to the central atom is identified individually and then listed, as a prefix, in front of the name o…

Isomers are two or more compounds that share the same chemical formula but differ in how their atoms are arranged in space.

Geometric (geometrical) isomerism arises in heteroleptic complexes — complexes bonded to more than one kind of ligand — because of the different geometric arrangements the ligands can adopt around the…

Optical isomers are mirror images of one another that cannot be superimposed on one another, no matter how they are rotated in space.

Linkage isomerism arises in a coordination compound that contains an ambidentate ligand — a ligand which possesses more than one kind of donor atom, so that it can attach itself to the central metal t…

Coordination isomerism arises in a compound that is built from both a cationic coordination entity and an anionic coordination entity, each centred on a different metal.

Ionisation isomerism arises when the counter ion of a complex salt — the ion lying outside the coordination sphere — is itself capable of acting as a ligand.

Solvate isomerism is closely related to ionisation isomerism, and takes the specific name hydrate isomerism in the particular case where the solvent involved is water.

Werner had already described what a coordination compound looks like — a central metal surrounded by a fixed number of ligands in a definite geometry — but his theory was silent on why this happens.

Valence Bond Theory pictures the formation of a coordination entity as a hybridisation event on the metal atom or ion.

The magnetic moment of a coordination compound can be measured experimentally through magnetic susceptibility measurements.

Valence Bond Theory does a reasonably good job of accounting for the formation, geometry, and magnetic behaviour of many coordination compounds.

Crystal Field Theory (CFT) takes a completely different starting point from VBT. It treats the metal–ligand bond as purely electrostatic (ionic), arising from the attraction and repulsion between the…

One of the most striking features of transition metal complexes is the sheer range of colours they display.

Crystal Field Theory is, to a large extent, genuinely successful — it gives a workable account of the formation, structures, colour, and magnetic properties of coordination compounds, and it does all…

A metal carbonyl is a coordination compound in which the ligand is carbon monoxide. When every ligand attached to the metal is CO, the compound is called homoleptic.

Coordination compounds are not just a theoretical curiosity — they occur naturally across the mineral, plant and animal worlds, and they are put to deliberate use across analytical chemistry, metallur…

- Coordination entity: A central metal ion/atom bonded to a fixed number of ligands (ions/molecules) via coordinate bonds. Example: .

These are the final answers printed at the end of the NCERT chapter. The book gives answers for some intext questions only — every question below links to our complete worked solution.

Higher-order thinking / exemplar-style practice problems.

Sample papers and previous-year board questions for this subject.