Question

Few isomers are given below. The correct statement regarding them are:
(i) $\left[Cr\right(H_{2}O{)}_6]C{l}_3$
(ii) $\left[Cr\right(H_{2}O{)}_{5}Cl]C{l}_2.H_{2}O$
(iii) $\left[Cr\right(H_{2}O{)}_{4}C{l}_2]Cl.2H_{2}O$

• A. (i),(ii) and (iii) are hydrate isomers
• B. (i),(ii) and (iii) are coordination isomers.
• C. (i),(ii) and (iii) are ionisation isomers.
• D. (i) and (ii) are stereo-isomers.

Answer 1

Answer: (A)

(i),(ii) and (iii) are hydrate isomers

Water molecules are exchanged inside and outside coordination sphere. The number of water molecules is different inside and outside the coordination sphere. These are called hydrate isomers.

(i) $\left[Cr\right(H_{2}O{)}_6]C{l}_3$ has six water molecules inside the coordination sphere and zero water molecules outside the coordination sphere.

(ii) $\left[Cr\right(H_{2}O{)}_{5}Cl]C{l}_2.H_{2}O$ has five water molecules inside the coordination sphere and one water molecules outside the coordination sphere.
(iii) $\left[Cr\right(H_{2}O{)}_{4}C{l}_2]Cl.2H_{2}O$ has four water molecules inside the coordination sphere and two water molecules outside the coordination sphere.