Which of the following statements is not correct?

The correct answer is (1) In oxyhaemoglobin, \(Fe^{2+}\) is paramagnetic.

In oxyhemoglobin, the iron ion (\(Fe^{2+}\) ) is diamagnetic, not paramagnetic. In oxyhemoglobin, the iron ion is coordinated to a heme group and binds to oxygen molecules. The binding of oxygen to the iron ion induces the formation of a complex in which the iron ion is in the ferrous (\(Fe^{2+}\)) state. In this state, the iron ion has a fully paired set of electrons and exhibits diamagnetic behavior.

Diamagnetic substances have all their electrons paired and are not attracted to an external magnetic field. In the case of oxyhemoglobin, the ferrous iron ion (\(Fe^{2+}\) ) is diamagnetic due to the presence of paired electrons.

Therefore, the correct statement will be:  in oxyhemoglobin, \(Fe^{2+}\) is diamagnetic. Rest of the statements are correct.