Question

The formal charge on cl in the structure shown for the perchlorate ion is ________?

1) -2
2) -1
3) 0
4) 1
5) 2

Answer 1

The formal charge on Cl in the perchlorate ion is 0, as the charge is delocalized over the oxygen atoms.

Step-by-step explanation:

The formal charge on Cl in the perchlorate ion is calculated based on the electrons assigned to the atom and the number of valence electrons for the neutral atom. In ClO₄⁻, each Cl atom has seven electrons assigned to it, and when we subtract this number from the number of valence electrons for the neutral Cl atom, we get 7-7=0. Therefore, the formal charge on Cl in the perchlorate ion structure is 0. The perchlorate ion has a charge of -1, which is delocalized over the four oxygen atoms, rather than being localized on the chlorine atom.