Question

Give reason

Q.NO2 dimerises to form N2O4

Answer 1

The monomer NO2 exists in equilibrium with its dimer N2O4.On cooling the unpaired electrons of 2 NO2 molecules combine together to form N-N bond in N2O4.

Answer 2

In the NO2 molecule the nitrogen atom has a single unpaired electron. The molecule will tend to dimerise so that this unpaired electron can be paired with another to form the N2O4 molecule.