Sulfuric acid
(sulphuric acid).
Molecular formula: H2SO4
(O = 65,25 %, S = 32,69 %, H = 2,06 %)
Molar mass = 98,078 ± 0,006
g·mol-1
Formerly called oil of vitriol. It is a mineral acid whose strength
(pKa = -3.0) is only exceeded by a few super-acids. It is miscible
with water in all proportions where it dissociates releasing
hydronium cations H3O+:
Pure sulfuric acid is a viscous, colorless and odorless liquid.
Various impurities often brown yellow color. Sometimes its
concentration is expressed in degrees
Baumé (symbol ° Be '), which actually measure the
density of liquid, which varies significantly depending on the
content of sulfuric acid.
Because hygroscopic nature of its, it can be used for drying. It is
therefore industrially used as drying agent (when it absorbs water or
water vapor of the substance to be dried, it is diluted).
Pure sulfuric acid is not encountered naturally on Earth in anhydrous
form, due to its great affinity for water, it is nevertheless found
in some volcanic lakes (see link
on Hydro-Land) and acid rain, which results from the oxidation of
acid H2SO3 sulfur resulting from the
dissolution of sulfur dioxide SO2 in the clouds, sulfur
dioxide is itself produced by the sulfur-containing fossil fuels.
Production.
Today the major industrial process most widely used, is called
"contact process" because requires contact with a catalyst. It will
be generated by hydration of sulfur trioxide SO3, itself
resulting from the natural oxidation of sulfur dioxide
SO2.
It can be produced with a purity of 100% substantially, but it tends
to release sulfur trioxide, approaching its boiling points of
337° C (610 K), where it gives the acid as 98, 3%, corresponding
to the azeotrope with equilibrium water:
Main Features:
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In water treatment, it is used by injection in water with a
diluted reagent (solutions).
The dissolution process is exothermic, and above 50° C can be
rapidly reached.
A formulation for water treatment.
Reaction mechanism of calcium bicarbonates (simplified
equations):
H2SO4 +
Ca[HCO3]2 >>> 2 CO2
+ H2O + CaSO4
.98.........162
or 10°F.....
(2x44=88)
............136
With 1 mg as H2SO4 added, there has (10/98) = 0.102° F for
lower TAC, and 0.898 mg as free CO2 and (96/98) = 0,98 mg/L as SO4
formed.
Storage.
Tightly closed and dry in a well ventilated area.
Storage temperature: no restrictions.
Uses.
Health-wise.
Sources : personal and Wikipedia, the free encyclopedia.