Lecture 9 Flashcards
What is the lewis definition of an acid?
an electron-pair acceptor
has a vacent electron orbital
What is the lewis definition of a base?
an electron pair donor
has a lone electron pair
What is a coordinate/dative bond?
When the two electrons come from the central atom
What makes a reaction an acid/base reaction?
When both forward and reverse reactions involve the transfer of a proton
What are the species in acid/base reactions that differ by a proton?
Conjugate acid-base pairs
What is a Bronstead definition of an acid?
A proton donor
What is a Bronstead definition of a base?
A proton acceptor
needs electron pair to accept proton
What can act as both an acid and a base?
Water
What happens in water when it is neutral?
H3O+ conc = OH- conc
What is used for measuring H3O+ because it is so small?
pH
Can OH- conc and H3O+ conc vary independantly?
No because of the equillibrium expression for autoprotolysis of water
What is complete dissociation?
When acids donate their protons essentially completely to water.
What does complete dissociation happen to?
Strong electrolyted
What do strong acids have in terms of K?
A large K value
What can be calculated from the stoichiometry of the dissociation reaction of strong acids?
H3O+ conc
What happens when strong bases react in water?
Essentially complete formation of hydroxide ion OH-
What is key about the K in strong base reactions?
K is very large, at equillibrium only products consist
What can be calculated from the stoichiometry of strong base reactions?
OH- concentration
What is resonance?
The spreading out of negative charge across more than one atom.
What happens to acids whose conjugate bases undergo resonance?
Tend to be stronger than those whose conjugate bases cannot.
