Interactive Chemistry Worksheets for Students
Sulfuric acid in its pure form is a colorless viscous liquid commonly called oil of vitriol
The chemical formula for sulfuric acid is H2SO4 and it is commercially available as a 96-98% solution or 18M H2SO4.
Concentrated sulfuric acid is covalent in nature as the acid is unionized. The atoms in the molecule are covalently bonded to one another. In this form sulfuric acid can be transported in stainless steel tankers.
If concentrated sulfuric acid is added to water the reaction is extremely exothermic due to formation of hydrogen ions.
H2SO4(l) ==> H+(aq) + HSO4-(aq) First ionization
HSO4-(aq) ==> H+(aq) + SO42-(aq) Second ionization
Sulfuric acid is made from elemental sulfur or from its compounds by converting them to sulfur dioxide.
S + O2 ==> SO2
Sulfur + oxygen ==> Sulfur dioxide
SO2 + O2 ==> SO3
Sulfur dioxide + oxygen ==> Sulfur trioxide
SO3 + H2SO4 ==> H2S2O7
Sulfur trioxide + sulfuric acid ==> Oleum
H2S2O7 + H2O ==> 2H2SO4
Olem + water ==> Sulfuric acid
The direct addition of water to sulfur trioxide is too violent. That is why the sulfur trioxide is dissolved in sulfuric acid to form oleum. The oleum is then added to water to produce sulfuric acid.