Analyzing Organic Reactions Flashcards
How is a Lewis acid defined?
An electron acceptor in the formation of a covalent bond
What do Lewis acids tend to be?
Electrophiles
How is a Lewis base defined?
An electron donor in the formation of a covalent bond
What do Lewis bases tend to be?
Nucleophiles
What are some qualities of a Lewis base?
Lewis bases have a lone pair of electrons that can be donated; they’re often anions; carry a negative charge
What happens when Lewis acids/bases interact?
They form coordinate covalent bonds
What is a coordinate covalent bond?
A covalent bond in which both electrons in the bond came from the same starting atom, the Lewis base
What’s the difference between the Lewis definition of acids/bases and the Bronsted-Lowry definition of acids/bases?
Lewis definition concerns itself with the transfer of electrons in the formation of a coordinate covalent bond; the Bronsted-Lowry definition focuses on proton transfer
What is the Bronsted-Lowry definition of an acid?
A species that can donate a proton (H+)
What is the Bronsted-Lowry definition of a base?
A species that can accept a proton
What are molecules called when they can either accept or donate protons?
Amphoteric
What are some examples of amphoteric molecules?
Water, Al(OH)3, HCO3-, HSO4-
What is the conjugate base and acid of water?
OH- and H3O+, respectively
When determining whether or not a molecule acts as an acid or base, what must be considered?
The type of solution the molecule is in
What does the acid dissociation constant, Ka, measure?
The strength of an acid in solution
In a dissociation of an acid HA, HA<-> H+ + A-, what is the equation for the equilibrium constant?
Ka=[H+][A-]/[HA]
How is the pKa calculated?
pKa= -logKa
What kind of pKa would an acidic molecule exhibit?
A smaller (or even negative) pKa
What kind of pKa would a basic molecule exhibit?
A larger pKa
What kind of pKa do strong acids have?
pKas below -2
What does a pKa of below -2 indicate?
A very strong acid that completely dissociates in solution
When will an acid-base reaction proceed, based on the strength of the reactants and products?
An acid-base reaction will proceed so long as the reactants are more reactive “stronger” than the products that they form
