Exemplar Problems

Problem 16 : Explain the concept of formal charge in Lewis structures. Calculate the formal charges for all atoms in the carbonate ion (CO₃²⁻).
Solution :

To calculate the formal charges for all atoms in the carbonate ion (CO₃²⁻), use the formula: Formal Charge (FC) = Valence Electrons - (Number of Bonds + Number of Lone Electrons)

  • For the carbon atom (C): +1
  • For the oxygen atoms (O): -1 (each)