Caustic Soda Pellets
Sodium Hydroxide
NaOH 40.00
DEFINITION
Content
97.0 per cent to 100.5 per cent Sodium Hydroxide.
CHARACTERS
Appearance
White or almost white, crystalline masses, supplied as pellets, sticks or slabs, deliquescent, readily absorbing carbon dioxide.
Solubility
Very soluble in water, freely soluble in ethanol (96 per cent).
IDENTIFICATION
A. pH minimum 11.0.
B. 2 ml of solution S gives reaction of sodium.
TESTS
Solution S
Carry out the procedure described below with caution. Dissolve 5.0 g in 12 ml of distilled water. Add 17 ml of hydrochloric acid R1, adjust to pH 7 with 1 M hydrochloric
acid and dilute to 50 ml with distilled water.
Appearance of solution
The solution is clear and colourless.
Dissolve 1.0 g in 10 ml of water.
Carbonates
Maximum 2.0 per cent, calculated as Na2CO3 as determined in the assay.
Chlorides
Maximum 50 ppm.
Sulphate
Maximum 50 ppm.
Iron
Maximum 10 ppm, determined on solution S.
Heavy metals
Maximum 20 ppm.
Sodium Hydroxide
NaOH 40.00
Caustic Soda Pellets
Sodium hydroxide [1310-73-2]
Sodium Hydroxide contains not less than 95.0 percent and not more than 100.5 percent of total alkali, calculated as NaOH, including not more than 3.0 percent of Na2CO3.
Caution—Exercise great care in handling Sodium Hydroxide, as it rapidly destroys tissues.
Identification— A solution (1 in 25) responds to the tests for Sodium.
Insoluble substances and organic matter— A solution (1 in 20) is complete, clear, and colorless to slightly colored.
Potassium— Acidify 5 mL of a solution (1 in 20) with 6 N acetic acid, then add 5 drops of sodium cobalt nitrite TS: no precipitate is formed.
Heavy metals— the limit is 0.003%.
Caustic Soda Pellets
NaOH Formula wt 40.00
Sodium Hydroxide
INS: 524 CAS: [1310-73-2]
DESCRIPTION
Sodium Hydroxide occurs as white or nearly white pellets, flakes, sticks, fused masses, or other forms. Upon exposure to air it readily absorbs carbon dioxide and
moisture. One gram dissolves in 1 mL of water. It is freely soluble in alcohol.
Function: pH control agent.
REQUIREMENTS
Identification: A 1:25 aqueous solution gives positive tests for Sodium.
Assay: Not less than 95.0% and not more than 100.5% of total alkali, calculated as NaOH.
Arsenic: Not more than 3 mg/kg.
Carbonate: (as Na2CO3) Not more than 3.0%.
Insoluble Substances and Organic Matter: Passes test.
Lead: Not more than 2 mg/kg.
Mercury: Not more than 0.1 mg/kg.
Sodium Hydroxide
NaOH
Formula Wt 40.00
CAS Number 1310-73-2
REQUIREMENTS
Assay: 97.0% NaOH min
Sodium Carbonate: 1.0% Na2CO3 max
MAXIMUM ALLOWABLE
Chloride (Cl): 0.005%
Nitrogen compounds (as N): 0.001%
Phosphate (PO4): 0.001%
Sulfate (SO4): 0.003%
Ammonium hydroxide precipitate: 0.02%
Heavy metals (as Ag): 0.002%
Iron (Fe): 0.001%
Mercury (Hg): 0.1 ppm
Nickel (Ni): 0.001%
Potassium (K): 0.02%
