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Sulfuric acid

Sulfuric acid
A bottle of 96% pure sulfuric acid
Names IUPAC name
Sulfuric acid
Other names
  • Oil of vitriol
  • Hydrogen sulfate
  • Dihydrogen sulfate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard100.028.763EC Number
  • 231-639-5
E numberE513 (acidity regulators, ...)2122 KEGG
RTECS number
  • WS5600000
UNII
UN number1830
  • InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)
    Key: QAOWNCQODCNURD-UHFFFAOYSA-N
  • InChI=1/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)
    Key: QAOWNCQODCNURD-UHFFFAOYAC
  • OS(=O)(=O)O
Properties H2SO4, sometimes expressed (HO)2SO2Molar mass98.07 g·mol Appearance Colorless viscous liquid OdorOdorless Density1.8302 g/cm, liquid Melting point10.31 °C (50.56 °F; 283.46 K) Boiling point337 °C (639 °F; 610 K)
When sulfuric acid is above 300 °C (572 °F; 573 K), it gradually decomposes to SO3 + H2Omiscible, exothermic Vapor pressure0.001 mmHg (20 °C) Acidity (pKa) pKa1 = strong
pKa2 = 2.0 Conjugate baseBisulfateViscosity26.7 cP (20 °C) Structure monoclinic C2/c
a = 818.1(2) pm, b = 469.60(10) pm, c = 856.3(2) pm
α = 90°, β = 111.39(3)°, γ = 90°
4 Thermochemistry 157 J/(mol·K) −814 kJ/mol 56 kJ/mol Hazards GHS labelling: DangerH290, H314P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501NFPA 704 (fire diamond)
3
0
2
W
OX
Flash pointNon-flammable 15 mg/m (IDLH), 1 mg/m (TWA), 2 mg/m (STEL) Lethal dose or concentration (LD, LC): 2140 mg/kg (rat, oral)
  • 50 mg/m (guinea pig, 8 h)
  • 510 mg/m (rat, 2 h)
  • 320 mg/m (mouse, 2 h)
  • 18 mg/m (guinea pig)
87 mg/m (guinea pig, 2.75 h) NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m
REL (Recommended)
TWA 1 mg/m
IDLH (Immediate danger)
15 mg/m Related compounds
Related strong acids
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formulaH2SO4. It is a colorless, odorless, and viscous liquid that is miscible with water.

Pure sulfuric acid does not occur naturally due to its strong affinity to water vapor; it is hygroscopic and readily absorbs water vapor from the air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. When sulfuric acid is added to water, a considerable amount of heat is released; thus, the reverse procedure of adding water to the acid is generally avoided since the heat released may boil the solution, spraying droplets of hot acid during the process. Upon contact with body tissue, sulfuric acid can cause severe acidicchemical burns and secondary thermal burns due to dehydration. Dilute sulfuric acid is substantially less hazardous without the oxidative and dehydrating properties. Nonetheless, it must be handled with care due to its acidity.

There are many methods for producing sulfuric acid, including the contact process, the wet sulfuric acid process, and the lead chamber process. Sulfuric acid is also a key substance in the chemical industry. It is most commonly used in fertilizer manufacture but is also important in mineral processing, oil refining, wastewater treating, and chemical synthesis. It has a wide range of end applications, including in domestic acidic drain cleaners, as an electrolyte in lead-acid batteries, as a dehydrating compound, and in various cleaning agents. Sulfuric acid can be obtained by dissolving sulfur trioxide in water.

Wikipedia source