Formal Charge in Molecules
This worksheet helps grade 9 students understand how to calculate and interpret formal charges in chemical structures, enhancing their knowledge of molecular stability and bonding.
Includes
Standards
Formal Charge Analysis
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Read each question carefully and provide your answer in the space provided. For calculations, show all your work. Remember the formula for formal charge: Formal Charge = (Valence Electrons) - (Non-bonding Electrons) - (1/2 Bonding Electrons).
1. The formal charge of an atom in a molecule is the hypothetical charge it would have if all bonds were shared between atoms.
2. A molecule with formal charges closest to for all atoms is generally more stable.
3. In a Lewis structure, non-bonding electrons are also known as pairs.
4. Which of the following is the correct formula to calculate formal charge?
FC = VE - NBE - BE
FC = VE - NBE - (1/2)BE
FC = VE + NBE + BE
FC = VE + NBE - (1/2)BE
5. What does a formal charge of zero on all atoms in a molecule generally indicate?
The molecule is highly reactive.
The molecule is unstable.
The molecule is likely the most stable resonance structure.
The molecule has an overall positive charge.
6. Draw the Lewis structure for carbon monoxide (CO) and calculate the formal charge for both carbon and oxygen atoms. Show your work.
7. Consider the sulfate ion (SO4^2-). Explain how formal charges can help determine the most plausible Lewis structure for this ion.
8. The sum of the formal charges in a neutral molecule must always be zero.
True
False
9. Formal charge is the actual charge on an atom in a molecule.
True
False