SULFURIC ACID(FUMING) OR OLEUM[H2SO4.xSO3]

CAS Number 8014-95-7

·         Linear Formula H₂SO₄ · (SO₃)_x

·         Molecular Weight 98.08

·          Beilstein Registry Number 2037554

·          MDL number MFCD00137792

·          PubChem Substance ID 329756351

Oleum (Latin oleum = "oil"), or fuming sulfuric acid, is a solution of various compositions of sulfur trioxide in sulfuric acid, or sometimes more specifically to disulfuric acid (also known as pyrosulfuric acid). Oleum is identified by the CAS number 8014-95-7.
Detailed d

Oleums can be described by the formula ySO₃.H₂O where y is the total molar sulfur trioxide content. The value of y can be varied, to include different oleums. They can also be described by the formula H₂SO₄.xSO₃ where x is now defined as the molar free sulfur trioxide content. Oleum is generally assessed according to the free SO₃ content by mass. It can also be expressed as a percentage of sulfuric acid strength; for oleum concentrations, that would be over 100%. For example, 10% oleum can also be expressed as H₂SO₄.0.13611SO₃, 1.0225SO₃.H₂O or 102.25% sulfuric acid. The conversion between % acid and % oleum is: % acid = 100 + 18/80 × % oleum

A value for x of 1 gives the empirical formula H₂S₂O₇ for disulfuric (pyrosulfuric) acid. Pure disulfuric acid itself is a solid at room temperature, melting at 36 °C and rarely used either in the laboratory or industrial processes.

Applications

Sulfuric acid production

Oleum is an important intermediate in the manufacture of sulfuric acid due to its high enthalpy of hydration. When SO₃ is added to water, rather than simply dissolving, it tends to form a fine mist of sulfuric acid, which is difficult to manage. However, SO₃ added to concentrated sulfuric acid readily dissolves, forming oleum which can then be diluted with water to produce additional concentrated sulfuric acid.^[1]

As an intermediate for transportation

Oleum is a useful form for transporting sulfuric acid compounds, typically in rail tank cars, between oil refineries (which produce various sulfur compounds as a byproduct of refining) and industrial consumers.

Certain compositions of oleum are solid at room temperature, and thus are safer to ship than when liquid. Solid oleum can then be converted into liquid at the destination through steam heating or dilution or concentration. This requires some care to prevent overheating and evaporation of sulfur trioxide. To extract it from a tank car requires careful heating using steam conduits within the tank car. Great care must be taken to avoid overheating, as this can increase the internal pressure within the tank car to a value exceeding the limit of the tank's safety valve.

In addition, oleum is less corrosive to metals than sulfuric acid, because there is no free water to attack the surfaces.^[2] Because of that, sulfuric acid is sometimes concentrated to oleum for in-plant pipelines and then diluted back to acid for use in industrial reactions.

In Richmond, California in 1993 a significant release occurred due to overheating, causing a release of sulfur trioxide^[3] that absorbed moisture from the atmosphere, creating a mist of micrometre-sized sulfuric acid particles that formed an inhalation health hazard.This mist produced adverse health effects on residents and workers over a wide area.

Organic chemistry

Oleum is a harsh reagent, and is highly corrosive. One important use of oleum as a reagent is the secondary nitration of nitrobenzene. The first nitration can occur with nitric acid in sulfuric acid, but this deactivates the ring towards further electrophilic substitution. A stronger reagent, oleum, is needed to introduce the second nitro group onto the aromatic ring.

PRICE

$811.81/KG OR $368.71/IB

For more information:

mobile: +2348039721941

contact person: emeaba uche

e-mail: emeabau@yahoo.com

website: www.franchiseminerals.com