Question

For the first row transition metals the `E^(ɵ)` value are:
`{:(underset(-1.18)(V),,underset(-0.91)(Cr),,underset(-1.18)(Mn),,underset(-0.44)(Fe),,underset(-0.28)(Co),,underset(-0.25)(Ni),underset(+0.34)(Cu)):}`
Explain the irregularity in the above values.

Answer 1

The `E^(Ɵ)(M^(2+)//M)` values are not regular which can be explained from the irregular variation of ionisation enthalpies `(Delta_(i)H_(1)+Delta_(i)H_(2))` and also the sublimation enthalpies which are relatively much less for manganese and vanadium.