$\left.\left[\mathrm{CoNH}_3\right)_4\left(\mathrm{NO}_2\right)_2\right] \mathrm{Cl}$ exhibits

• A

  linkage isomerism, geometrical isomerism and optical isomerism
• B

  linkage isomerism, ionization, isomerism and optical isomerism
• Correct answer
  C

  linkage isomerism, ionization isomerism and geometrical isomerism
• D

  ionization isomerism, geometrical isomerism and optical isomerism

Solution

The compound $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\left(\mathrm{NO}_2\right)_2\right]$ $\mathrm{Cl}$ exhibits linkage, ionisation and geometrical isomerism. Linkage isomers: $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\left(\mathrm{NO}_2\right)_2\right]$ $\mathrm{Cl}$ and $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4(\mathrm{ONO})_2\right] \mathrm{Cl}$ Ionisation isomers: $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\left(\mathrm{NO}_2\right)_2\right]$ $\mathrm{Cl}$ and $\left.\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4\left(\mathrm{NO}_2\right) \mathrm{Cl}\right)\right] \mathrm{NO}_2$

Hence, the correct answer is option: 'C'.