**We will continue talking about acid/base chemistry. Bring the last 5 slides from lecture 6 to lecture 7.**

Structure and Acidity Hybridization: The greater the % s character of C, the more stable the anion and the more acidic the C-H bond is

Structure and Acidity Resonance delocalization: the greater the delocalization of negative charge in the anion, the stronger the acid HA is Compare the acidities of ethanol and acid acetic acid, both of which contain an -OH group –ionization of the O-H bond of an alcohol gives an anion for which there is no resonance stabilization

Structure and Acidity –Ionization of the O-H bond of a carboxylic acid gives a resonance-stabilized anion. Acetate anion is a more stable anion than ethoxide anion and, therefore, acetic acid is a stronger acid than ethanol

Structure and Acidity Electron-withdrawing inductive effect: withdrawal of electron density from the H-A bond increases the acidity of HA –a carboxylic acid is a stronger acid than an alcohol because of (1) the resonance stabilization of the carboxylate anion and (2) the electron-withdrawing inductive effect of the adjacent carbonyl group

Position of equilibrium Favors reaction of the stronger acid and stronger base to give the weaker acid and weaker base

Position of equilibrium Reaction of acetic acid and ammonia

Position of equilibrium Calculation of K eq –write the equilibrium constant for this acid/base reaction, multiply by [H 3 O + ]/H 3 O + ], rearrange terms, substitute values, and solve

Position of equilibrium Reaction of acetic acid and sodium bicarbonate

Lewis Acids and Bases Lewis acid: accepts a pair of electrons to form a new covalent bond Lewis base: donates a pair of electrons to form a new covalent bond

Lewis Acids and Bases