Some General Aspects
Lecture Three covers the following points:-
-Some General Aspects
-Definition of Some Terms
Standard Solution:
It is a reagent of known concentration that is used to carry out a titrimetric analysis
A Primary Standard Substance:
It is a highly purified compound that serves as a reference material in all volumetric titrimetric methods.
Important properties of a primary standard substance:
The substance should be readily purified.
It should not be hygroscopic.
It should not be contain hydrate water.
It should be readily soluble.
It should have a relatively high equivalent weight.
It should be available and not too expensive.
It should be stable toward air.
It should be stable on storage.
It should not undergo any side-reaction.
Compounds that meet or even approach these criteria are very few, and only a limited number of primary standard substances are available to the chemist.
The compounds that are less pure must sometimes be employed in lieu of a primary standard. The purity of such a secondary standard must be established by careful analysis.
Ideal Standard Solution:
Be sufficiently stable .
React rapidly with the analyte.
React more or less completely with the analyte.
Undergo a selective reaction with the analyte.
The standard solution is prepared by dissolving an accurate weight of pure reagent in water this is then diluted to an exactly known volume.
Lecture Three covers the following points:-
-Some General Aspects
-Definition of Some Terms
Standard Solution:
It is a reagent of known concentration that is used to carry out a titrimetric analysis
A Primary Standard Substance:
It is a highly purified compound that serves as a reference material in all volumetric titrimetric methods.
Important properties of a primary standard substance:
The substance should be readily purified.
It should not be hygroscopic.
It should not be contain hydrate water.
It should be readily soluble.
It should have a relatively high equivalent weight.
It should be available and not too expensive.
It should be stable toward air.
It should be stable on storage.
It should not undergo any side-reaction.
Compounds that meet or even approach these criteria are very few, and only a limited number of primary standard substances are available to the chemist.
The compounds that are less pure must sometimes be employed in lieu of a primary standard. The purity of such a secondary standard must be established by careful analysis.
Ideal Standard Solution:
Be sufficiently stable .
React rapidly with the analyte.
React more or less completely with the analyte.
Undergo a selective reaction with the analyte.
The standard solution is prepared by dissolving an accurate weight of pure reagent in water this is then diluted to an exactly known volume.
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