A Lewis structure of formate (HCO2-) places a double bond on one O and a single bond plus three lone pairs on the other O.
The formal charge on the singly-bonded oxygen is:
- Acheck_circle
-1
- B
-2
- C
0
- D
+1
Explanation
FC = 6 - 6 (lone pair e-) - 1 (half of bonding e-) = -1.