TOPIC 4: Volumetric Analysis Flashcards
The determination of the VOLUME of a solution of KNOWN CONCENTRATION required to react with a given amount of substance to be analyzed.
Volumetric Analysis
Importance of Volumetric Analysis
- It is used in determining the ______ of drugs.
- ________________ - determination of contaminants and pH.
- ______________ - determination of salt, vit and fatty acid content.
- It is used in determining the purity of drugs.
- Water treatment - determination of contaminants and pH.
- Food industry - determination of salt, vit and fatty acid content.
A common laboratory method of quantitative chemical analysis where a solution of known concentration is used to determine the concentration of an unknown solution.
Titration
Parts of a titration set-up:
- Analyte/Titrand
- Standard solution/ Volumetric Solution/Titrant
- Indicator
The chemical substance being analyzed or the active constituent in the sample.
Analyte
A solution which concentration is accurately known.
Standard Solution
A chemical which changes color at or very near the endpoint.
Indicator
Point during a titration when an indicator shows that the amount of reactant necessary for a complete reaction has been added to a solution.
Endpoint (practical)
The theoretical point at which equivalent amounts of each substance have reacted.
Equivalence Point / Stoichiometric Point / Theoretical Endpoint
Reaction between an acid and a base to form salt of water.
Neutralization
Reactions that from an insoluble precipitate.
Precipitimetry
Reaction between metal ions and a ligand.
Complexometry
Reaction that involves the - transfer of electrons.
Redox Titration
Indicators are referred to as ?
TS or Test Solutions
Used to avoid errors during titration.
Indicators
Indicators’ usual concentration is ?
0.05% with 0.1 to 0.2ml of indicator used for 10ml of the analyte
Number of moles of reactive unit in a compound which reacts or takes the place of one mole of Hydrogen ion.
Equivalent
Weight that is chemically equivalent to the reacting power of one of one atomic weight of hydrogen.
Equivalent Weight
1/1000 of Eq. weight is called ?
milliequivalent weight
Strength in grams equivalent to milliliter of standard solution or the weight of a substance chemically equivalent to 1 ml of a standard solution.
Titer
A solution of known concentration or a solution whose exact concentration is known.
Standard Solution
Process of determining exact concentration of a solution.
Standardization
2 Types of Volumetric Solution
Primary Standard
Secondary Standard
Chemically pure solid substance almost 99.9% pure used in the standardization of a solution.
Primary Standard
Substance that is not necessarily pure but whose exact purity is known.
Secondary Standard
A standard solution is a commonly used ?
secondary standard
To standardize only one of the solutions by using a primary standard and the other is standardized by using a secondary standard.
Common practice
Primary Standard for acid solutions:
Anhydrous Na2CO3
CaCO3
TrisHydroxymethylAminoMethane (THAM)
Primary Standard for alkali solutions:
Benzoic acid
Potassium biphthalate
Sulfamic acid
