Primary standards

 

Primary standards

Primary standards

¨  Primary standards are standards that are recognized & established by National Institute of Standards and Technology United State of America, National Physical laboratory United Kingdom or some other such organization.

¨  Primary standards are highly pure and stable reagents having no water of hydration.

¨  Primary standards that are used to standardize Volumetric  solution are also termed as Volumetric Standards.

¨  Some of the Volumetric standards are mentioned below

¨  Arsenic Trioxide (As2O3)

              Molecular Weight= 197.8

¨  Benzoic Acid (C7H6O2)

               Molecular Weight = 122.1

¨  Calcium Carbonate (CaCO3)

               Molecular Weight = 100.09

¨  Ferrous Ethylenediammonium Sulfate (Fe(C2H10N2)(SO4)2,4H2O)

              Molecular Weight =382.1

¨  Potassium Bromate (KBrO3)

              Molecular weight3= 167.0

¨  Potassium Dichromate (K2Cr2O7)

Molecular weight = 294.185

¨  Potassium Hydrogen Phthalate (C8H5KO4)

Molecular weight = 204.2

¨  Potassium Iodate (KIO3)

Molecular weight = 214

¨  Sodium Carbonate Anhydrous (Na2CO)

Molecular weight = 106.0

¨  Sodium Chloride (NaCl)

 Molecular weight = 58.44

¨  Sulfanilic Acid (C6H7NO3S)

Molecular weight = 173.2

¨  Trometamol (C4H11NO3)

Molecular weight = 121.1

¨  Zinc (Zn)

Atomic weight = 65.4