Match the compounds given in Column I with the oxidation state of cobalt present in it (given in column II) and assign the correct code.
| Column I (Compound) |
Column II (Oxidation state of Co) |
||
|---|---|---|---|
| A. | $\left[\mathrm{Co}(\mathrm{NCS})\left(\mathrm{NH}_3\right)_5\right]\left(\mathrm{SO}_3\right)$ | 1. | +4 |
| B. | $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right] \mathrm{SO}_4$ | 2. | 0 |
| C. | $\mathrm{Na}_4\left[\mathrm{Co}\left(\mathrm{S}_2 \mathrm{O}_3\right)_3\right]$ | 3. | +2 |
| D. | $\left[\mathrm{CO}_2(\mathrm{CO})_8\right]$ | 4. | +3 |
Assertion (A) Toxic metal ions are removed by the chelating ligands.
Reason (R) Chelate complexes tend to be more stable.
Assertion (A) $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}_6\right)\right] \mathrm{Cl}_2$ and $\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{Cl}_2$ are reducing in nature.
Reason (R) Unpaired electrons are present in their d-orbitals.
Assertion (A) Linkage isomerism arises in coordination compounds containing ambidentate ligand.
Reason (R) Ambidentate ligand has two different donor atoms.
Assertion (A) Complexes of $M X_6$ and $M X_5 L$ type ( $X$ and $L$ are unidentate) do not show geometrical isomerism.
Reason (R) Geometrical isomerism is not shown by complexes of coordination number 6.