Exam 2: Set 1: Lewis Acids and Bases

Lewis acid

contains an empty orbital that is capable of accepting a lone pair

Lewis base

has a lone pair that it can donate to form a bond with an acid

Bronsted acid

has one or more proton(s) that can be donated to a base

Bronsted base

has a lone pair that can ‘accept’ a proton from an acid

pKa

the relative strength of an acid/base. Lower values mean it is a strong acid. Higher values mean it is a strong base.

weak acids

have a strong conjugate base

strong acids

have a weak conjugate base

conjugate base

the base formed when an acid loses a proton in an acid-base reaction

conjugate acid

the acid formed when a base gains a proton in an acid-base reaction

stability factors of a conjugate base/acid

1. Atomic size/electronegativity

2. Resonance stabilization

3. inductive effect

4. orbital hybridization

inductive effect

the way in which highly electronegative atoms such as iodine or fluorine draw electron density towards themselves in a molecule

how orbital changes stability

orbitals with higher ‘s’ character hold electron density more stably.

‘s’ character

the amount that ‘s’ orbital contributes to a hybrid orbital. For example, sp has a higher ‘s’ character than sp³