Why is `Co^(2+)` easily oxidised to `Co^(3+)` in presence of a strong-field ligand?

(a) state the reason for each of the following situations: (i) Co^(+2) is easily oxidised to Co^(+3) in presence of a strong ligand.

Explain the following given appropriate reason: i) Nickel does not form low spin octahedral complexes. ii) The pi -complexes are known for the transition metals only. iii) Co^(2+) is easily oxidised to Co^(3+) in the presence of a strong ligand.

Co^(2+) is easily oxidised to Co^(3+) in the presence of a strong ligand. Explain.

Explain the following observations : Although Co^(2+) ion appears to be stable, it is easily oxidised to Co^(3+) ion in the presence of a strong ligand.

The strong field ligand is "

The strong field ligand is "

(a) What is meant by the term lanthanoid contraction ? What is it due to and what consequences does it have on the chemistry of elements following lanthanoids in the periodic table ? (b) Explain the following observations : (i) Cu^(+) ion is unstable in aqueous solutions . (ii) Although Co^(2+) ion appears to be stable , it is easily oxidised to Co^(3+) ion in the presence of a strong ligand. (iii) The E_(Mn^(2+)//Mn)^(@) value for manganese is much more than expected from the trend for other elements in the series.

(a) What is meant by the term lanthanoid contraction ? What is it due to and what consequences does it have on the chemistry of elements following lanthanoids in the periodic table ? (b) Explain the following observations : (i) Cu^(+) ion is unstable in aqueous solutions . (ii) Although Co^(2+) ion appears to be stable , it is easily oxidised to Co^(3+) ion in the presence of a strong ligand. (iii) The E_(Mn^(2+)//Mn)^(@) value for manganese is much more than expected from the trend for other elements in the series.

Assign reason for each of the following : (i) Transition elements exhibit paramagnetic behaviour . (ii) Co^(2+) is easily oxidised in the presence of a strong ligand