The nitric acid in the form of a gas is present in the form of a monomer. It contains only one unpaired electron and is therefore paramagnetic. In the solid state, it exists as a dimer (N2O2). There is no unpaired electron in its dimer form, hence it is diamagnetic.
Why is nitric oxide paramagnetic in gaseous state but the solid obtained on cooling it is diamagnetic?
Why is nitric oxide paramagnetic in gaseous state but the solid obtained on cooling it is diamagnetic?