CHEM 1127Q Lecture Notes - Lecture 26: Formal Charge, Lewis Structure, Chemical Polarity

• School: UConn
• Department: Chemistry
• Course: CHEM 1127Q
• Professor: Niluka Wasalathanthri

Document Summary

Topics covered: 7. 4 formal charges and resonance, 7. 6 molecular structure and. The formal charge of an atom in a molecule is the hypothetical charge the atom would have if we could redistribute the electrons in the bonds evenly between the atoms. The sum of the formal charges of all atoms in a molecule must be zero. The sum of the formal charges in an ion should be equal the charge of the ion. Using formal charge to predict molecular structure. When there is more than one possible structure, the best arrangement is determined by the following guidelines: 1) a lewis structure in which all formal charges are zero is preferred. 2) small formal charges are preferred to large formal charges. A resonance structure is one of two or more lewis structures for a single molecule that cannot by represented accurately by only one lewis structure. A bond angle is the angle between any two bonds that include a common atom,