Question

Preparation of [Co(NH3)4CO3]NO3 Experiment

Classify your ligands.

Which ions satisfy the primary and secondary valence?

How many electrons are around the central metal? Does it satisfy the 18 electron rule? Is it stable?

Answer 1

Ligand is an atom/compound ion which can donate a pair of electrons to central metal atom in a complex compound.

In the given complex, NH3 and CO₃^-2 are the ligands which satisfy the secondary valency of the metal atom.

Secondary valency of the metal is the valency when it forms the complex compound.

Primary valency of the metal is nothing but the group number of the metal (generally that is no.of electrons lost by it to attain nearest inert gas configuration)

Nitrate ion satisfies the primary valency of the metal.

Around the central metal atom Co the no.of electrons = 4 pairs are donated by NH3 and one pair is donated by carbonate ion.

Oxidation state of the metal atom is: +3

Therefore total number of electrons = (27-3) + 8+2 = 34

It do not satisfy the EAN rule of the complex compounds. Hence, it is unstable.