b. Types of Salts. There are four types of reactions possible between acids
and bases as we classified them (strong or weak) earlier. These are as follows:
Relative strength of common acids and bases
STRONG ACIDS
WEAK ACIDS
HCl
Hydrochloric acid
HC2H3O2 (HAC) Acetic acid
H2SO4
Sulfuric acid
H2CO3
Carbonic acid
H3PO4
Phosphoric acid
H3BO3
Boric acid
STRONG BASES
WEAK BASES
KOH
Potassium hydroxide
Fe(OH) 2
Ferrous hydroxide
NaOH
Sodium hydroxide
Al(OH)3
Aluminum
hydroxide
NH3
Ammonia
_____________________________________
* Ca(OH) 2
Calcium hydroxide
Mg(OH) 2
Magnesium hydroxide
MgO
Magnesium oxide___________
* Notice that Ca(OH) 2, Mg(OH) 2, and MgO which forms Mg(OH) 2 in water are
chemically classified as strong bases because of their high degree of dissociation.
Because they are only slightly soluble in water, they produce low concentrations of
the hydroxide (OH-) ion in solution. Since calcium hydroxide and magnesium
hydroxide do not produce tissue damage, they can be safely used as therapeutic
agents (e.g., antacids).
Table 2-1. Relative strength of common acids and bases.
(1)
Strong acid and strong base.
HCl+ NaOH ---> NaCl + H2O
(2)
Weak acid and weak base.
2H2CO3 + Fe(OH)2 ---> Fe(HCO3)2 + 2H2O
(3)
Strong acid and weak base.
2HCl + Fe(OH)2 -----> FeCl2 + 2H2O
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