The manganate and permanganate ions are tetrahedral; the p-
bonding takes place by overlap of p orbitals of oxygen with d orbitals
of manganese The green manganate is paramagnetic because of one
unpaired electron but the permanganate is diamagnetic due to the
absence of unpaired electron Acidified permanganate solution oxidises oxalates to carbon dioxide,
iron(II) to iron(III), nitrites to nitrates and iodides to free iodine The half-reactions of reductants are:
COO
–
COO
–
5
10CO2 + 10e
–
5 Fe2+ ® 5 Fe3+ + 5e–
5NO2
– + 5H2O ® 5NO3
– + 10H+ + l0e–
10I– ® 5I2 + 10e–
The full reaction can be written by adding the half-reaction for
KMnO4 to the half-reaction of the reducing agent, balancing wherever
necessary