Why primary and secondary standard solutions are needed in analysis.?

Answer 1

Primary standards have some peculiar properties

1. They are nonsensitive to atmospheric oxygen
2. They have known formula and molecular weight
3. They are usually high molecular weight compounds
4. They have a constant concentration /uniform composition for a long period of time
5. They are powerful reactants

Secondary standards are

1. Influenced by atmosphere/environment
2. Concentration change over time
3. Usually powerful reactants
4. Usually cheap & easy to use

Zeryawkal Ergetie

(Msc in pharmaceutical Analysis )

Answer 2

Primary StandardsA primary standard is a reagent that is extremely pure, stable, has no waters of hydration, and has a high molecular weight. Secondary StandardsA secondary standard is a standard that is prepared in the laboratory for a specific analysis. It is usually standardized against a primary standard.

Answer 3

solution that changes it's strength with the passage of time.

Answer 4

Standards are necessary for the validation of analytical chemistry methods and instruments, to resolve litigations, to implement a qulity system in laboratory etc.

Answer 5

Primary standard solutions are certified standard materials; secondary standard solutions are standardized with the help of primary standard solutions.