How would you account for the following ? (i) Of the d^(4) species , Cr^(2+) is strongly reducting while manganese (III) is strongely oxidizing. (ii) Cobalt (III) is stable in aqueous solution but in the presence of complexingreagents , it is easily oxidized. (iii) The d^(1) configuration is very unstable in ions.

How would you account for the following ? (i) Of the d^(4) species ,

1.	How would you account for the following ? (i) Of the d^(4) species , Cr^(2+) is strongly reducting while manganese (III) is strongely oxidizing. (ii) Cobalt (III) is stable in aqueous solution but in the presence of complexingreagents , it is easily oxidized. (iii) The d^(1) configuration is very unstable in ions.
Answer» Solution :(i) Refer to page (ii) CO(III)has GREATER tendency to form coordination complexes than Co(II). Hence, in the PRESENCE of ligands, C(II) changes to Co(III) , i.e., is easily oxidized. (iii) The IONS with `d^(1)` configuration have the tendency to losethe only electron present in d-subshell to acquire stable `d^(0)` configuration .Hence, they are unstable and undergo oxidationor disproportionation.