TOPIC 5: Alkalimetry and Acidimetry Flashcards
Principles of Acid-base Tritimetry
• Types of Titration based on the number of Volumetric Solution
- Direct Assay
- Residual Assay
• Blank Determination
Used to monitor the reaction.
pH indicator
This reaction usually occurs between acid and base, hydroxide ions and hydrogen protons, resulting in the formation of water.
Neutralization
This reactions are chemical processes whereby an amount of an acid has reacted with an equivalent amount of a base with the production of salt and water.
Neutralization
The measurement of basic in substances by titration with a standard acid.
Acidimetry
Involves the determination of acidic substances by titration with a standard base solution.
Alkalimetry
In Acid-Base Reaction,
Titrant + Analyte =
Salt and Water
An ______ is any substance which in water ionizes to give hydrogen ions (hydronium ions*).
Acid
A _____ is any substance which in water ionizes to give hydroxyl ions.
Base
Use WATER as the solvent for dissolving the analyte samples for the titration.
Aqueous titrimetry
Use ORGANIC SOLVENTS for dissolving the sample.
Non-aqueous titrimetry
Strong Acid + Strong Base:
Phenolphthalein, methyl red, methyl orange
Weak Acid + Strong Base:
Phenolphthalein
Strong Acid + Weak Base:
Methyl red
Weak Acid + Weak Base:
No indicator
Weak Base + Salt:
Crystal violet, Quinaldine red, malachite green
Relatively Strong Base:
Methyl red, methyl orange
Weak acid:
Azo-violet, o-nitro-aniline (very WA)
Strong Acid:
Thymol blue
Burette used in Bases
Mohr’s Burette
(Rubber Tube + Pinchcock)
Burette used in Acids
Geissler’s Burette
(Glass Stopper)
Types of Titration Based On The Number of Volumetric Solution
Direct
Residual / Back Titration
Titrant is added into the analyte until chemical equivalent amounts of them reacts together.
Direct Titration
Described as the amount of volumetric solution in excess. The excess is back titrated with another volumetric solution.
Residual / Back Titration
ONLY 1 VOLUMETRIC SOLN/STD, SOLUTION
Direct Titration
USES 2 VOLUMETRIC SOLN.
Residual Titration
❖ Volatile
❖ Sample is insoluble in water
❖ Reaction with standard solution is slow
❖ Sample does not give a distinct endpoint with an indicator by direct titration (No sharp endpoint)
Residual Titration
Carried in the same manner as the actual test BUT without the sample.
Blank Test
