Question

(b) How would you account for the following -
(i) The transition elements have high enthalpies of atomization (ii) Cu (II) is paramagnetic but Cu (1) is diamagnetic.
(iii) Name the element which show only (more stable) +3 oxidation state
(in 3d series)​

Answer 1

1. Transition elements which have very high boiling point have high enthalpy of atomisation which is an important factor in determining the standard electrode potential
2. Cu+2 has (Ar) 3d9 as electronic configuration while Cu+1 has (Ar) 3d10 as electronic configuration. So we can see when we fill d orbital in Cu+2 there is one unpaired electron while in Cu+1 the d orbital has all paired electrons. Therefore, unpaired electron indicate paramagnetic character in Cu+2 while paired electrons indicate diamagnetic character in Cu+1
3. Scandium is the element which show only +3 oxidation state