Sulfuric Acid
H2SO4
Mol. Wt. 98.08
Sulfuric acid
〔7664-93-9〕
Sulfuric Acid contains not less than 94.0% of sulfuric acid (H2SO4).
Content
Description
Sulfuric Acid is a colorless or slightly brownish, transparent or
almost transparent, viscous liquid.
Identification
(2)
(1)
Sulfuric Acid solution (1 → 100) is strongly acidic.
Sulfuric Acid solution (1 → 100) responds to all tests for Sulfate as described
in the Qualitative Tests.
Purity
(1)
Chloride
Not more than 0.005% as Cl (2.0 g, Control solution 0.01
mol/l hydrochloric acid 0.30 ml).
(2)
Nitrate
Not more than 10 µg/g as NO3.
Weigh 5 g of Sulfuric Acid, add gradually to 8 ml of water, add 1 ml of a solution of
brucine in sulfuric acid (1 → 500) and sulfuric acid to make 25 ml, shake well, and
warm at about 80℃ for 10 minutes. The color of the solution is not darker than that of
the solution prepared as follows: Measure 0.5 ml of Nitrate Standard Solution, add 8
ml of water, add 5 ml of sulfuric acid gradually, add 1 ml of a solution of brucine in
sulfuric acid (1 → 500) and sulfuric acid to make 25 ml, shake well, and warm at
about 80℃ for 10 minutes.
(3)
Heavy metals
Not more than 20 µg/g as Pb.
Test Solution Weigh 1.0 g of Sulfuric Acid, add to 10 ml of water, neutralize with
ammonia TS, and add 2 ml of diluted acetic acid (1 → 20) and water to make 50 ml.
Control Solution Measure exactly 2 ml of Lead Standard Solution, add 2 ml of
diluted acetic acid (1 → 20) and water to make 50 ml.
(4)
Iron
Not more than 0.010% as Fe (0.10 g, Method 2, Control solution Iron
Standard Solution 1.0 ml).
Not more than 4.0 µg/g as As2O3 (0.50 g Method 1, Apparatus B).
(5)
Arsenic
(6)
Readily oxidizable substances Not more than 20 µg/g as SO3.
Weigh 8 g of Sulfuric Acid, add to 10 ml of cold water while cooling, and add 0.10
ml of 0.02 mol/l potassium permanganate. The pink color of the solution does not
disappear within 5 minutes.
Residue on Ignition
Assay
Not more than 0.02% (10 g).
Weigh accurately about 2 g of Sulfuric Acid, add to 50 ml of water, and
cool. Add water to make exactly 100 ml, measure exactly 25 ml of this solution, and
titrate with 0.5 mol/l sodium hydroxide (indicator: 1−2 drops of bromothymol blue TS).
1 ml of 0.5 mol/l sodium hydroxide = 24.520 mg of H2SO4