REDUCING AGENT
OXIDIZING AGENT
(1)
Gives up electrons
(1)
Gains electrons
(2)
Oxidized during reaction
(2)
Reduced during reaction
(3)
Unusually low valence
(3)
Unusually high valence
state compared to most
state compared to most
common state
common state
2-8.
ACIDS AND BASES
The two most important classifications of compounds in inorganic chemistry are
acids and bases. The following discussion forms the groundwork for understanding
some of the most important chemical changes which you will encounter.
a. Classical Acid-Base Theory. Svante Arrhenius, in 1887, published the first
satisfactory explanation of the acid-base phenomena that had been observed by
chemists.
(1) Acids. Arrhenius defined an acid as a compound that donates protons
+
(H ) in solution. Examples would be any of the compounds you learned to name as
acids earlier in this subcourse.
HOH
HCl -----> H+ + Cl -
HOH
-----> H+ + HSO4 -
H2SO4
NOTE: The HOH (H2O), which indicates that water is the solvent in these reactions.
Both HCl and H 2SO4 contribute protons in solution.
(2) Bases. Arrhenius defined a base as any compound that donates
hydroxyl (OH-) ions in solution. Again, you should be familiar with several examples
from your nomenclature studies.
HOH
NaOH -----> Na+ + OH -
HOH
KOH -----> K+ + OH -
(3) Discussion. These classical definitions are based on the
dissociation of the compounds into ions in solution. This implies that all acids and
bases must contain exchangeable hydrogen and hydroxyl ions, respectively, in their
MD0803
2-12