Formal Charge

Front

What is formal charge?

Back

Formal charge is a theoretical charge assigned to an atom in a molecule, calculated based on the number of valence electrons, the number of bonds, and the number of non-bonding electrons.

Front

How is formal charge calculated?

Back

Formal charge = (Valence electrons) - (Non-bonding electrons) - 0.5*(Bonding electrons)

Front

What is the formal charge on an atom with 6 valence electrons, 2 non-bonding electrons, and 4 bonding electrons?

Back

Formal charge = 6 - 2 - 0.5*(4) = 6 - 2 - 2 = 2.

Front

What does a formal charge of 0 indicate?

Back

A formal charge of 0 indicates that the atom has the same number of electrons as it would in its neutral state.

Front

What is the significance of formal charge in Lewis structures?

Back

Formal charge helps determine the most stable Lewis structure by minimizing the formal charges on atoms.

Front

What is the formal charge on an oxygen atom with 6 valence electrons, 4 non-bonding electrons, and 2 bonding electrons?

Back

Formal charge = 6 - 4 - 0.5*(2) = 6 - 4 - 1 = 1.

Front

What is the formal charge on a fluorine atom in a molecule?

Back

Fluorine typically has a formal charge of 0 when it forms one bond and has three lone pairs.

Front

What is the formal charge on a bromine atom with 7 valence electrons, 2 non-bonding electrons, and 6 bonding electrons?

Back

Formal charge = 7 - 2 - 0.5*(6) = 7 - 2 - 3 = 2.

Front

What are resonance structures?

Back

Resonance structures are different Lewis structures that represent the same molecule, showing the delocalization of electrons.

Front

How does formal charge relate to resonance structures?

Back

In resonance structures, the formal charge helps identify the most stable structure by minimizing charges.