Polar Covalent Bonds: Acids and Bases
Organic molecules often have polar covalent bonds as a result of unsymmetrical electron sharing caused by differences in the electronegativity of atoms. The polarity of a molecule is measured by its dipole moment, . (+) and () indicate formal charges on atoms in molecules to keep track of valence electrons around an atom. Some substances must be shown as a resonance hybrid of two or more resonance forms that differ by the location of electrons. A Brønsted(–Lowry) acid donates a proton. A Brønsted(–Lowry) base accepts a proton. The strength Brønsted acid is related to the negative logarithm of the acidity constant, pKa. Weaker acids have higher pKa’s. A Lewis acid has an empty orbital that can accept an electron pair. A Lewis base can donate an unshared electron pair. In condensed structures C-C and C-H are implied. Skeletal structures show bonds and not C or H (C is shown as a junction of two lines) – other atoms are shown. Molecular models are useful for representing structures for study. Noncovalent interactions have several types: dipole- dipole, dispersion, and hydrogen bond forces.
Document information
- Uploaded on
- November 11, 2023
- Number of pages
- 44
- Written in
- 2023/2024
- Type
- Presentation
- Person
- Unknown
