Formal Charge Calculator

Formula

The formula to calculate the formal charge is:

\[ FC = V - (LP + 0.5 \times BE) \]

Where:

FC is the formal charge
V is the number of valence electrons
LP is the number of lone pair electrons
BE is the number of bound electrons

What is Formal Charge?

A formal charge is defined as the electrical charge of an individual atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.

Example Calculation

Example 1:

Valence Electrons (V): 6
Lone Pair Electrons (LP): 4
Bound Electrons (BE): 4

Step 1: Calculate the formal charge:

\[ FC = 6 - (4 + 0.5 \times 4) = 6 - (4 + 2) = 6 - 6 = 0 \]

Example 2:

Valence Electrons (V): 5
Lone Pair Electrons (LP): 2
Bound Electrons (BE): 6

Step 1: Calculate the formal charge:

\[ FC = 5 - (2 + 0.5 \times 6) = 5 - (2 + 3) = 5 - 5 = 0 \]