1. Acid & Base Definitions
Arrhenius Theory
Acid-substance that contains hydrogen and produces H+ in aqeous solution (soln.)
any protonic acid is an Arrhenius acid: H2SO4, HCl, HNO3 ....
Base-substance that contains the hydroxyl (OH) group and produces hydroxide ions (OH-) in aqeous soln.
Metal hydroxides (hydroxyl bases) are Arrhenius bases
Neutralization: H+(aq) + OH-(aq)  H2O(l)
HA(aq)+ OH-(aq)  H2O(l) + A-(aq)

2. Brønsted-Lowry Theory
Acids-Proton donor
Any hydrogen containing compound capable of releasing a proton: All acids that we have discussed so far.
Bases-Proton acceptor
Metal hydroxides, ammonia, ammonia derivatives and more.
Acid-Base Rxns: HA(aq) + B(aq)  A-(aq) + BH+(aq)
acid base
HNO3 + H2O - + H3O+
proton transfer
H2O + NH3  OH- + NH4+

3. Lewis Theory
Acids - lone pair acceptor
any electron deficient compound: BF3
Bases - lone pair donor
any compound with a lone pair for donation: NH3, CO, O2 , ...
Acid-Base rxn involves the formation of a coordinate covalent bond
Coordinate Covalent Bond

4. Lewis Acid-Base Reaction

5. Autoionization H2O + H2O  H3O+ + OH- acid base
What kind of acid is shown in the above reaction? Base?
Arrhenius, Brønsted-Lowry & Lewis Acid
Arrhenius, Brønsted-Lowry & Lewis Base

6. Amphoterism
Amphoterism - the ability of a substance to act as an acid or a base.
A substance that exhibits amphoterism is said to be amphoteric
Water is amphoteric because it can act as an acid or a base.
Specifically, water is amphiprotic because it can either be a proton donar or acceptor (Brønsted-Lowery definition or an acid & base)
Many insoluble metal hydroxides are amphoteric:
Cu(OH)2(s) + 2H+(aq)  Cu2+(aq) + 2 H2O
base acid
Cu(OH)2(s)+2OH-(aq)  Cu(OH)42-(aq)
acid base