Question

Match List-I with List-II:

List – I	List – II
(a) [Co(NH3)6] [Cr(CN)6]	(i) Linkage isomerism
(b) [Co(NH3)3 (NO2)3]	(ii) Solvate isomerism
(c) [Cr(H2O)6]Cl3	(iii) Coordination isomerism
(d) cis-[CrCl2(ox)2]3-	(iv) Optical isomerism

Choose the correct answer from the options given below:

• A. (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)
• B. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
• C. (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
• D. (a)-(iv), (b)-(ii), (c)-(iii), (d)-(i)

Answer 1

The correct option is A (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

(a) If the complex is a salt having both cation and anion as complex ions then the ligands can exchange position between cation and anion. This results in the formation of coordination isomers, So, (a)-(iii)

(b) Linkage isomerism arises in a coordination compound containing ambidentate ligand. $N{O}_2$is an ambidentate ligand and is capable of coordinating in more than one way
i.e. $N{O}_2^{-}\text{and}ON{O}^{-}$. So (b)-(i)

(c) Solvaate isomerism also known as hydrate isomerism occurs where where water is involved as a solvent. The aqua complex $\left[Cr\right(H_{2}O{)}_6]C{l}_3$ (violet) and its solvate isomer $\left[Cr\right(H_{2}O{)}_{5}Cl]C{l}_2.H_{2}O$ (grey-green). So, (c)-(ii)

(d) Optical isomers are mirror images that cannot be superimposed on one another. These are called as enantiomers. The molecules or ions that cannot be superimposed are called chiral. The two forms are called dextro (d) and laevo (l) depending upon the direction they rotate the plane of polarised light in a polarimeter (d rotates to the right, l to the left). Optical isomerism is common in octahedral complexes involving didentate ligands.
In a coordination entity of the type [CrCl₂(ox)₂]^3- only the cis-isomer shows optical activity