Textbook Question
By moving an electron pair, draw a better Lewis structure that minimizes formal charges.
(b)
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1. A Review of General Chemistry
Formal Charges
1:51 minutesProblem 28e
Textbook Question
Calculate the formal charge of the indicated atom in the following molecules or ions.
(e) 
Verified step by step guidance1
Step 1: Recall the formula for calculating formal charge: Formal Charge = (Valence Electrons) - (Non-bonding Electrons) - (1/2 × Bonding Electrons).
Step 2: Identify the atom in question (Nitrogen in this case) and determine its number of valence electrons. Nitrogen belongs to Group 15 in the periodic table, so it has 5 valence electrons.
Step 3: Count the number of non-bonding electrons (lone pairs) on the nitrogen atom. In the structure, nitrogen has one lone pair, which corresponds to 2 non-bonding electrons.
Step 4: Count the number of bonding electrons around the nitrogen atom. Nitrogen is bonded to three hydrogen atoms and one carbon atom, forming four single bonds. Each single bond contributes 2 bonding electrons, so the total bonding electrons are 8.
Step 5: Plug the values into the formula: Formal Charge = 5 (valence electrons) - 2 (non-bonding electrons) - (1/2 × 8 bonding electrons). Simplify the expression to determine the formal charge.
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Video duration:
1mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Formal Charge
Formal charge is a theoretical charge assigned to an atom in a molecule, calculated based on the number of valence electrons, the number of non-bonding electrons, and half the number of bonding electrons. It helps in determining the most stable structure of a molecule by minimizing the formal charges across the atoms.
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Lewis Structures
Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They provide a visual representation of the arrangement of electrons, which is essential for calculating formal charges and understanding molecular geometry.
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Valence Electrons
Valence electrons are the electrons in the outermost shell of an atom that are involved in forming bonds with other atoms. Knowing the number of valence electrons for each atom is crucial for drawing Lewis structures and calculating formal charges, as it directly influences the bonding and stability of the molecule.
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