12. Salts
Acid (proton donor) and base (proton acceptor) react upon mixing and a salt is formed.
Base |
+ |
Acid |
|
Salt |
+ |
Water |
NaOH |
+ |
HCl |
|
NaCl |
+ |
H2O |
NH3 |
+ |
HNO3 |
|
NH4NO3 |
+ |
H2O |
KOH |
+ |
HOAc |
|
KOAc |
+ |
H2O |
Salts are ionic compounds. On dissolving in water they break up into ions.
Salt |
|
Positive Ion |
+ |
Negative Ion |
NaCl |
|
Na+ |
+ |
Cl- |
NH4NO3 |
|
NH4+ |
+ |
NO3- |
KOAc |
|
K+ |
+ |
OAc- |
The positive ion is an acid.
Positive Ion = Acid |
Conjugate Base |
Na+ |
NaOH |
NH4+ |
NH3 |
K+ |
KOH |
The negative ion is a base.
Negative Ion = Base |
Conjugate Acid |
Cl- |
HCl |
NO3- |
HNO3 |
OAc- |
HOAc |
Depending on the strength of those acids and bases, the solution of a salt in water may be neutral, acidic or basic.
Summary
|
On dissolving in water salts break up into ions.
The positive ion is an acid, the negative ion is a base.
The solution of a salt in water may be neutral, acidic or basic.
|