Volumetric Analysis Flashcards
Also known as titration methods
Volumetric methods
Based on determining the quantity of a reagent of known
concentration (titrant or standard solution) that is required to
react completely with a solution of unknown concentration
(analyte)
Volumetric methods
A reagent of known concentration that is used
to carry out a volumetric titration
Standard solution/titrant
the point in a titration when the amount of added
standard reagent is equivalent to the amount of analyte
Equivalence point
the point in a titration when a physical change occurs that is
associated with the condition of chemical equivalence
End point
The difference in volume or mass between the
equivalence point and the end point (Vep – Veq or mep – meq)
Titration error
added to the analyte solution to produce an observable
physical change (signaling the end point) at or near the equivalence point
Indicators
a highly purified compound that serves as a reference
material in titrations and in other analytical methods
Primary standard
a compound whose purity has been determined by
chemical analysis and serves as the working standard material for
titrations and for many other analyses
Secondary standard
a process in which the excess of a standard solution used
to consume an analyte is determined by titration with a second standard
solution.
Back-titration
a carefully determined mass of a primary standard is dissolved in a
suitable solvent and diluted to a known volume in a volumetric flask
Direct method
the titrant to be standardized is used to titrate (1) a known mass of a
primary standard, (2) a known mass of a secondary standard, or (3) a measured
volume of another standard solution
Standardization
Type of curve: important observations are confined to small region surrounding the
equivalence point, p-function of analyte is plotted as a function of titrant volume
Sigmoidal curve
Type of curve; the vertical axis represents an instrument reading that is
directly proportional to the concentration of the analyte or the titrant, measurements
are made on both sides of, but well away from, the equivalence point
Linear segment curve
Type of double displacement reaction between acids and bases to produce a
salt and water
Neutralization
