[CHEM 1120] LAB#3: Acid -
Base Titration
Experiment an unknown monoprotic organic acid is analyzed with standardized base
generalized reaction HA(aq) + NaOH(aq) → NaA(aq) + H2O(l)
The reaction between a KNOWN MASS of the organic acid and a standardized solution of
NaOH is monitored by...changes in pH as the reaction progresses
phenolphthalein colors & function colorless in acid, pink in base; visual indicator of endpoint
end point pink; enough base has been added to neutralize the amount of acid that was originally
present (bc initial acid was unknown molarity)
A crude titration is completed initially to ensure that...a reasonable quantity of acid is analyzed in
the potentiometric titration.
potentiometric titration a volumetric method in which the potential between two electrodes is
measured as a function of the added reagent volume
A titration curve is constructed to...determine the molar mass and pKa of an unknown acid.
_____ also may be needed to identify the unknown acid.the melting point
equipment needed a buret, a clamp and ring stand, pH meter with electrode, and hot
plate/magnetic stirrer
goals for experiment1. draw/label titration curve
2. identify unknown
Base Titration
Experiment an unknown monoprotic organic acid is analyzed with standardized base
generalized reaction HA(aq) + NaOH(aq) → NaA(aq) + H2O(l)
The reaction between a KNOWN MASS of the organic acid and a standardized solution of
NaOH is monitored by...changes in pH as the reaction progresses
phenolphthalein colors & function colorless in acid, pink in base; visual indicator of endpoint
end point pink; enough base has been added to neutralize the amount of acid that was originally
present (bc initial acid was unknown molarity)
A crude titration is completed initially to ensure that...a reasonable quantity of acid is analyzed in
the potentiometric titration.
potentiometric titration a volumetric method in which the potential between two electrodes is
measured as a function of the added reagent volume
A titration curve is constructed to...determine the molar mass and pKa of an unknown acid.
_____ also may be needed to identify the unknown acid.the melting point
equipment needed a buret, a clamp and ring stand, pH meter with electrode, and hot
plate/magnetic stirrer
goals for experiment1. draw/label titration curve
2. identify unknown
