Titration is a process used to determine the concentration of an unknown substance. It involves adding a measured volume of the unknown sample and titrating it with a standard solution until the equivalence point is reached. The equivalence point is identified using an indicator that changes color at the exact point when the amounts of reacting substances are equivalent. The volume of standard solution used is then used to calculate the concentration of the original unknown sample.

1. Titration – process of determining the volume of a standard solution that will
be required to react completely with a a mesured amount of a sample
containing the substance under analysis.
A measured
volume of the
vinegar is
placed in a
flask.
5.0 mL
A few drops of
phenolpthalein
areadded
After an initial buret reading, standard
solution of 0.1N NaOH is added slowly
Near the end of the titration the indicator
momentarily changes to pink but goes back to
colorless with swirling
When the end point is
reached (equivalence
point), a tiny excess of
OH- is present, shown by
the permanent change of
color to pink.
The difference
between the
final buret
reading and the
initial buret
reading gives
the volume of
the standard
NaOH used
35.2 mL

2. At the equivalence point
Amount of solute (standard solution) = amount of solute (unknown sample)
Number of meq (std soln) = number of meq (unknown sample)
N V (Std. soln) = N V (unknown sample)

3. Determination of the N of CH3COOH in vinegar
N V CH3COOH = N VNaOH
Titration Process
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