The chlorine nitrate molecule \(\left(\mathrm{ClONO}_{2}\right)\) is believed to be involved in the destruction of ozone in the Antarctic stratosphere. Draw a plausible Lewis structure for the molecule.

You must count the total number of valence electrons in the molecule. Each Oxygen (O) atom contributes 6 valence electrons, the Nitrogen (N) atom contributes 5 valence electrons, and the Chlorine (Cl) atom contributes 7 valence electrons. Combining all of these, the total number of valence electrons available for the \(\mathrm{ClONO}_{2}\) molecule is \(2*6 + 5 + 7 = 24\) electrons.

Chlorine (Cl) is the least electronegative atom, it should be the central atom. Nitrogen (N) and Oxygen (O) atoms are arranged around it. The skeletal structure will look like this; O-N-Cl-O.

A single bond, that represents a pair of shared electrons, is drawn between each pair of bonded atoms (O-N, N-Cl and Cl-O), consuming 2*3 = 6 from the total valence electrons. Now, 18 electrons remain (24 initially - 6 used for bonds). Distribute the remaining electrons to each atom, starting from the outermost one (the O atoms in this case), until you run out of electrons or the octet rule is satisfied for each atom. Each of the O atoms receives 6 electrons (now having 8 including the covalent bond), consuming 2*6 = 12 more electrons. Now, 6 electrons remain (18 initially - 12 used now). The remaining 6 electrons are distributed to the N and Cl atoms by giving three electrons to each atom. Now each atom has obtained an octet of electrons.

Formalize the bond structure. The single line between each atom represents the sharing of 2 electrons. Also, pairs of dots represent two nonbonding electrons. The final Lewis structure is as follows: O = N - Cl - OWhere '-' represents a single bond and '=' represents a double bond. Each atom is surrounded by eight electrons, fulfilling the octet rule.