LESSON 7
TITRATION
7-1.
DISCUSSION
One of the basic methods of analytical chemistry is titration. Titration is the
incremental addition of a titrant into a known volume of titrating fluid in the presence of
an indicator that identifies the neutralization point. Titration is based on the following
principle: "One equivalent weight of a substance will react exactly with one equivalent
weight of another substance." Equivalent weight refers to the reacting ability of a
substance. When performing a titration, the concentration of the solutions involved
MUST be expressed in terms of the concentration units that indicate reacting strength,
Eq/L or mEq/L.
a. The number of equivalents or milliequivalents present in a given volume of
solution indicates the reacting strength of a solution. Since titration is based on the
reacting strength of one solution versus the reacting strength of another solution
(usually an acid versus a base), the Eq/L concentration of the acid times the volume of
the acid is equal to the Eq/L concentration of the base times the volume of the base. A
familiar formula that states these facts is:
C1V1 = C2V2
Where:
C1 = Eq/L or mEq/L concentration of the acid
V1 = Volume of the acid
C2 = Eq/L or mEq/L concentration of the base
V2 = Volume of the base
NOTE:
It is not crucial that the variables follow the above format. However, it is
crucial that the appropriate concentration and volume be multiplied.
b. Associated Terms Follow:
(1) Acidimetry. Acidimetry is defined as the determination of the
concentration of an unknown acid by using a standard base (a base in which the exact
concentration is known).
(2) Alkalimetry. Alkalimetry is defined as the determination of the
concentration of an unknown base by using a standard acid.
MD0837
7-2