Type of isomerism exhibited by compounds $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]…
Type of isomerism exhibited by compounds $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{Cl}_3,\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_5 \mathrm{Cl}\right] \mathrm{Cl}_2 \cdot \mathrm{H}_2 \mathrm{O},\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_4 \mathrm{Cl}_2\right] \mathrm{Cl}. 2\mathrm{H}_2 \mathrm{O}$ and the value of coordination number $(\mathrm{CN})$ of central metal ion in all these compounds, respectively is:
Ionisation isomerism, $\mathrm{CN}=4$
Solvate isomerism, $\mathrm{CN}=6$
Geometrical isomerism, $\mathrm{CN}=4$
Optical isomerism, $\mathrm{CN}=4$
Solution
Solvate isomerism differ by whether or not a solvent molecule is directly bonded to the metal ion or merely present as free solvent molecules in the crystal lattice.
- $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{Cl}_3,\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_5 \mathrm{Cl}\right]\mathrm{Cl}_2 . \mathrm{H}_2 \mathrm{O}$ and $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_4 \mathrm{Cl}_2\right] \mathrm{Cl} 2 \mathrm{H}_2 \mathrm{O}$ show solvate isomerism.
- Co-ordination number of $\mathrm{Cr}=6$