# Determine the formal charge on each atom in each of the following molecules or ions.?

Determine the formal charge on each atom in each of the following molecules or ions.

(a) SCO S C O_

(b) NO3- (nitrate ion) N+1 O(attached by a double bond) O O_

(c) CS2 C S S_

(d) HCO2H (formic acid) H C O O H_

• KEY: = is a double bond, – is a single bond

(a) SCO has 16 valence electrons. S=C=O

S and O have two unshared electrons.

According to what the other girl said,

S, C, and O all have a formal charge of ZERO.

(b) 24 valence electrons

2 N-O bonds, 1 N=O bond

N: formal charge of 1

O single bond: formal bond of -1

O=double bond: formal charge of 0

(c) 16 valence electrons

S=C=S

Carbon: formal charge of 0

Sulfur: formal charge of 0 (it has four unshared electrons)

(d) C-O, C-H, C=O-H (combine these, sry)

Carbon: 0 formal charge

Both Hydrogen: 0 formal charge

Single-bond oxygen: -1 formal charge

Double-bond oxygen: +1 formal charge

Hope this helps!

• +4 +5 +1 -3

• Sco Lewis Structure

• Draw the Lewis structures for each, and the formal charge on each atom will be:

FC = # of valence electrons on atom – # of lone pair electrons on the atom – half of the atom’s shared electrons.