Sulfuric(VI) acid

The discovery of sulfuric acid is credited to the 8th century Muslim chemist and alchemist, Jabir ibn Hayyan (Geber). The acid was later studied by 9th century Persian physician and alchemist Ibn Zakariya al-Razi (Rhazes), who obtained the substance by dry distillation of minerals including iron(II) sulfate heptahydrate, FeSO₄·7H₂O, and copper(II) sulfate pentahydrate, CuSO₄·5H₂O.
In the 17th century, the German-Dutch chemist Johann Glauber prepared sulfuric acid by burning sulfur together with saltpeter (potassium nitrate, KNO₃), in the presence of steam
Sulfuric acid created by John Roebuck's process only approached a 35–40% concentration.
Later refinements to the lead-chamber process by French chemist Joseph-Louis Gay-Lussac and British chemist John Glover improved the yield to 78%.
Throughout the 18th century, this could only be made by dry distilling minerals in a technique similar to the original alchemical processes.
In 1831, British vinegar merchant Peregrine Phillips patented the contact process, which was a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. Today, nearly all of the world's sulfuric acid is produced using this method.

Reported in EPA TSCA Inventory.

OSHA PEL: TWA 1 mg/m³
ACGIH TLV: TWA 1 mg/m³; STEL 3 mg/m³; Suspected Human Carcinogen (Contained in strong inorganic mists); (Proposed: TWA 0.2 mg/m³; Suspected Human Carcinogen (Contained in strong inorganic mists))
DFG MAK: 1 mg/m³
NIOSH REL: (Sulfuric Acid) TWA 1 mg/m³
DOT Classification:  8; Label: Corrosive

 Sulfuric acid (CAS NO.7664-93-9) ,its occupational chemical analysis uses OSHA: #ID-113 or NIOSH: Acids, inorganic, 7903.

Sulfuric acid (alternative spelling sulphuric acid), with the cas number 7664-93-9, is a highly corrosive strong mineral acid with the molecular formula H₂ SO₄. It is a pungent-ethereal, colorless to slightly yellow viscous liquid which is soluble in water at all concentrations.Sometimes, it may be dark brown as dyed during its industrial production process in order to alert people to its hazards.

Physical properties about Sulfuric acid are: (1)ACD/LogP: -1.114; (2)ACD/LogD (pH 5.5): -5.61; (3)ACD/LogD (pH 7.4): -5.61; (4)ACD/BCF (pH 5.5): 1.00; (5)ACD/BCF (pH 7.4): 1.00; (6)#H bond acceptors: 4; (7)#H bond donors: 2; (8)Index of Refraction: 1.537; (9)Molar Refractivity: 13.925 cm³; (10)Molar Volume: 44.58 cm³; (11)Polarizability: 5.52 10-24cm³; (12)Surface Tension: 124.13500213623 dyne/cm; (13)Density: 2.2 g/cm³; (14)Enthalpy of Vaporization: 62.935 kJ/mol; (15)Boiling Point: 330.001 °C at 760 mmHg

Preparation of Sulfuric acid: The manufacture of Sulfuric acid (CAS NO.7664-93-9) by the lead chamberprocess involves oxidation of sulfur to sulfur dioxide by oxygen, further oxidation of sulfur dioxide to sulfur trioxide with nitrogen dioxide, and, finally, hydrolysis of sulfur trioxide.

S + O₂ → SO₂
2NO + O₂→ 2NO₂
SO₂ + NO₂ → SO₃ + NO
SO₃ + H₂O → H₂SO₄

Modifications of the process include towers to recover excess nitrogen oxides and to increase the final acid concentration from 65% (chamber acid) to 78% (tower acid).
The contact process has evolved to become the method of choice for sulfuric acid manufacture because of the ability of the process to produce stronger acid.

S + O₂ → SO₂
2SO₂ + O₂ → 2SO₃
SO₃ + H₂O → H₂SO₄

In the process, sulfur and oxygen are converted to sulfur dioxide at 1000 °C and then cooled to 420 °C. The sulfur dioxide and oxygen enter the converter, which contains a catalyst such as vanadium pentoxide (V2O5). About 60 to 65% of the sulfur dioxide is converted by an exothermic reaction to sulfur trioxide in the first layer with a 2 to 4-second contact time. The gas leaves the converter at 600°C and is cooled to 400°C before it enters the second layer of catalyst. After the third layer, about 95% of the sulfur dioxide is converted into sulfur trioxide. The mixture is then fed to the initial absorption tower, where the sulfur trioxide is hydrated to sulfuric acid after which the gas mixture is reheated to 420 °C and enters the fourth layer of catalyst that gives overall a 99.7% conversion of sulfur dioxide to sulfur trioxide. It is cooled and then fed to the final absorption tower and hydrated to sulfuric acid. The final sulfuric acid concentration is 98 to 99% (1 to 2% water). A small amount of this acid is recycled by adding some water and recirculating into the towers to pick up more sulfur trioxide.

Uses of Sulfuric acid: Although Sulfuric acid is the common starting raw material, other sources of Sulfuric acid (CAS NO.7664-93-9) can be used, including iron, copper, lead, nickel, and zinc sulfides. Hydrogen sulfide, a by-product of petroleum refining and natural gas refining, can be burned to sulfur dioxide. Gypsum (CaSO₄) can also be used but needs high temperatures to be converted to sulfur dioxide. Other uses for it include the manufacture of fertilizers, chemicals, inorganic pigments, petroleum refining, etching, as a catalyst in alkylation processes, in electroplating baths, for pickling and other operations in iron and steel production, in rayon and film manufacture, in the making of explosives, and in nonferrous metallurgy.

When you are using this chemical, please be cautious about it as the following:
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice;
Never add water to this product;
In case of accident or if you feel unwell, seek medical advice immediately (show label where possible);?
Wear suitable protective clothing and gloves;

You can still convert the following datas into molecular structure:
(1)InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4);
(2)InChIKey=QAOWNCQODCNURD-UHFFFAOYSA-N;
(3)SmilesS(=O)(=O)(O)O;

The toxicity data is as follows: