Iris Bai 1E wrote:Use the formula FC=V-(L+S) to determine the formal charge. The structure that has more atoms with a formal charge of 0 has lower energy.

For part a) we can calculate the formal charge of the left molecule with the O to the left of Cl having a formal charge of 0 [6-(4+

(2))], the Cl having a formal charge of 0, the O below Cl 0, and the O to the right of Cl 0 for a total formal charge of 0. This structure has all atoms with a formal charge of 0

The right molecule has the O to the left of Cl having a formal charge of -1, the Cl +2, O below Cl -1, and O to the left of Cl 0 which gives us 3 atoms with a formal charge other than 0

Therefore, the structure to the left has lower energy.