Salt Analysis
1) Determination of calcium chloride dihydrate
Aim :
To determine the quality and quantity of calcium chloride dihydrate in a sample
Material required:
1) Sodium hydroxide 1N
2) Dilute HCl TS 5%
3) Naphthol green TS ( 0.02 g in 100 ml of H2O )
4) Murexide indicator
Procedure:
1) Weigh accurately about 1 g of calcium chloride dihydrate , or the corresponding
weight of a hydrate, transfer to a 250-ml beaker, and dissolve in a mixture of 100 ml
of water and 5 ml of dilute hydrochloric acid TS.
2) Transfer the solution to a 250-ml volumetric flask, dilute with water to volume and
mix.
3) Pipet 50 ml of the solution into a suitable container, add 100 ml of water, 15 ml of
sodium hydroxide TS, 40 mg of murexide indicator (amm. purpurate) and 3 ml of
naphthol green TS
4) Titrate with 0.05 M disodium ethylenediaminetetra-acetate until the solution is deep
blue in colour.
Calculation :
Each ml of 0.05 M disodium ethylenediaminetetraacetate is equivalent to 5.55 mg of CaCl2;
7.35 mg of CaCl2 · 2H2O; or 10.95 mg of CaCl2 · 6H2O.
2) Determination of potassium chloride
Aim :
To determine the quality and quantity of potassium chloride in a given sample
Material required:
1) Ammonium thiocyanate 0.1N
2) Silver nitrate 0.1 N
3) Nitric acid 50% ratio 1:1 with water
4) Ferric aluminium sulphate TS ( 50g in 300 ml water , add 6 ml of h2so4)
5) Nitrobenzene
Procedure:
1) Dissolve about 250 mg of the dried sample, accurately weighed in 50 ml of
water in a glass-stoppered flask.
2) Add, while agitating, 50 ml of 0.1 N silver nitrate, 3 ml of nitric acid, and 5 ml of
nitrobenzene, shake vigorously, add 2 ml of ferric ammonium sulfate TS
3) Titrate the excess silver nitrate with 0.1 N ammonium thiocyanate.
Calculation :
Each ml of 0.1 N silver nitrate is equivalent to
7.456 mg of KCl.
3) Determination of magnesium sulphate hepta hydrate
Aim :
To determine the quality and quantity of magnesium sulphate hepta hydrate in a given
sample
Material required:
1) Ammonia buffer solution pH 10
2) Eriochrome black T indicator ( 0.1g eriochrome black T in 8 ml 95% of ethanol make
up to 10 ml using 95% of ethanol )
3) Disodium EDTA 0.05 M
Procedure:
1) Weigh accurately about 1 g, and transfer to a 250 mL beaker with 50 mL of water.
2) Add 5 mL of pH 10 ammoniacal buffer solution and addt 50 mg of Eriochrome Black
T indicator mixture , appearance of red colour
3) Titrate with 0.1 M EDTA volumetric solution to a clear blue colour (and disappearance
of the last trace of red).
Calculation:
One millilitre of 0.1 M EDTA corresponds to 0.02465 g of MgSO4 · 7H2O.
4) Determination of sodium chloride
Aim :
To determine the quality and quantity of sodium chloride in a given sample.
Material required:
1) Ammonium thiocyanate 0.1N
2) Silver nitrate 0.1 N
3) Nitric acid 50% ratio 1:1 with water
4) Ferric aluminium sulphate TS ( 50g in 300 ml water , add 6 ml of h2so4)
5) Nitrobenzene
Procedure :
1) Dissolve about 250 mg of the dried sample, accurately weighed in 50 ml of
2) water in a glass-stoppered flask.
3) Add, while agitating, 50 ml of 0.1 N silver nitrate, 3 ml of nitric acid, and 5 ml of
nitrobenzene, shake vigorously, add 2 ml of ferric ammonium sulfate TS
4) Titrate the excess silver nitrate with 0.1 N ammonium thiocyanate.
Calculation:
One ml of 0.1N silver nitrate corresponds to 0.005844 g of Nacl.
5) Determination of magnesium chloride hexahydrate
Aim :
To determine the quality and quantity of magnesium chloride hexahydrate in a given sample
Material required:
1) Ammonia chloride buffer pH 10
2) Eriochrome black T TS
3) Disodium ethylenediaminetetraacetate 0.05M
Procedure
1) Dissolve about 450 mg of the sample, accurately weighed, in 25 ml of water.
2) Add 5 ml of ammonia/ammonium chloride buffer TS and 0.1 ml of
eriochrome black TS ( appearance of red colour )
3) Titrate with 0.05 M disodium ethylenediaminetetraacetate until the solution is blue in
colour.
Calculation :
Each ml of 0.05 M disodium ethylenediaminetetra-acetate is equivalent to 10.16 mg of
MgCl2 · 6H2O.
