Page 102 - Pharmaceutical_Analytical_Chemistry_1_Theoretical_Notes_Level_1

Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)

Non-Aqueous Titrations

Non aqueous titration is the titration of substances dissolved in solvent
other than water.

Definition It deals with the analysis in a medium completely free from water.
It is the most common titrimetric procedure used in pharmacopeial
assays.

1) The reactant is insoluble in water.

2) The reactant is reactive with water.
Reasons

for Non 3) The sample is too weak acid or too weak base (too weak acids or bases
aqueous cannot be titrated in aqueous solution due to the amphoteric behavior of

titrations water (i.e water can react as an acid on titration with a base and act as a
base on titration with acid). So, water will compete with the sample if it is

a weak acid or a weak base.

Remember

Brønsted-Lowry theory

acid is proton donor - base is proton acceptor

+ -
HA  H + A

Acid conjugate base
+
+
B + H  HB
base conjugate acid

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