Answer / ananth

Primary standard :
Primary standards are the materials having high purity
values under specified conditions which can be used to
standardise the volumetric solutions.This primary stadards
also used to prepare the solutions which are necessay for
the calibration of analytical instruments.


Secondary standards:
Generally volumetric solutions are
known as secondary standards

Answer / anna

primary standard: is a reagent that is stable, pure, it is not hydrated and is of known concentration. for example, Na2CO3, NaCl etc

secondary standard: is a reagent that is unstabe and very reactive with atmosphere so, have not a conctant concentration. For example, NaOH, H2SO4, etc

Answer / kamal kishore kashyap

Primary standard are the compounds having reagent(analyte)
of high purity and can directly used for perpration of
standard solutions.
Example:- Nacl is primary standard for AgNO3
NaOH is primary standard for HCl


Secondary Standard solutions are analysed against primary
standard solutions. Basically these are perpared in
laboratory for specific analysis.

Answer / areeba anees

A primary standard solution is one whose concentration does not change with a passage of time. It is a stable substance. It does not react with the atmosphere.
Whereas a secondary standard solution is an unstable one whose concentration changes with a passage of time.

Answer / faisal jameel

Primary standard
1- are those whose purity is already known.
2-non reactive.
3-used to validiate secondary standard.
4-are thermostable.
Ex- NACL, SODIUM OXALATE, NA2CO3.

Secondary standard-
1-reacts with moisture.
2-not thermostable.
3-validiate by primary standard.
4- not stable at room temperature.
Ex-NAOH, HCL, H2SO2

Answer / abdul razaque

primary standards are those substances having constant concentration ( they do not react with moist)
secondary standard are those substances whose variable concentration ( they react with moist)

Answer / habib dawar

primary standard are those which have highest stability,purity,stability and doesn't fluctuate in variable environmental condition.

while secondary standard are those which have impurity(<96-98%),unstable and fluctuate with environmental condition(like sensitive to moist,light,)

Answer / aatika firdous

Primary standard is a compound of sufficient purity from which standard solution of known normality can pe prepared by direct weighing of it and diluting to a defined volume of solution

Answer / komal jain

A compound of known purity from which a standard solution can be prepared by weighing a known quantity and dissolving it in definite volume of solvent.
Example : KHP , K2CO3

Answer / adil abbas

This compound of known purity from which a standard solution.

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