Sulfuric acid

Sulfuric acid
Space-filling model
Ball-and-stick model
S=O bond length = 142.2 pm,
S-O bond length = 157.4 pm,
O-H bond length = 97 pm
Names
IUPAC name
Sulfuric acid
Other names
  • Oil of vitriol
  • Hydrogen sulfate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.028.763 Edit this at Wikidata
EC Number
  • 231-639-5
E number E513 (acidity regulators, ...)
2122
KEGG
RTECS number
  • WS5600000
UNII
UN number 1830
  • InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4) checkY
    Key: QAOWNCQODCNURD-UHFFFAOYSA-N checkY
  • 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)2SO2
Molar mass 98.079 g/mol
Appearance Colorless viscous liquid
Odor Odorless
Density 1.8302 g/cm3, liquid[1]
Melting point 10.31[1] °C (50.56 °F; 283.46 K)
Boiling point 337[1] °C (639 °F; 610 K)
When sulfuric acid is above 300 °C (572 °F; 573 K), it gradually decomposes to SO3 + H2O
miscible, exothermic
Vapor pressure 0.001 mmHg (20 °C)[2]
Acidity (pKa) pKa1 = −2.8
pKa2 = 1.99
Conjugate base Bisulfate
Viscosity 26.7 cP (20 °C)
Structure[3]
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)[4]
−814 kJ/mol[4]
Hazards
GHS labelling:
GHS05: Corrosive GHS06: Toxic
Danger
H314
P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)
Flash point Non-flammable
15 mg/m3 (IDLH), 1 mg/m3 (TWA), 2 mg/m3 (STEL)
Lethal dose or concentration (LD, LC):
2140 mg/kg (rat, oral)[5]
  • 50 mg/m3 (guinea pig, 8 hr)
  • 510 mg/m3 (rat, 2 hr)
  • 320 mg/m3 (mouse, 2 hr)
  • 18 mg/m3 (guinea pig)
[5]
87 mg/m3 (guinea pig, 2.75 hr)[5]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m3[2]
REL (Recommended)
TWA 1 mg/m3[2]
IDLH (Immediate danger)
15 mg/m3[2]
Safety data sheet (SDS) External SDS
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).
☒N verify (what is checkY☒N ?)

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 formula H2SO4. It is a colorless, odorless, and viscous liquid that is soluble with water.[6]

Structure of sulfuric acid

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.[6] Concentrated sulfuric acid is highly corrosive towards other materials, from rocks to metals, since it is an oxidant with powerful dehydrating properties. 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. Upon addition of sulfuric acid 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 acidic chemical burns and secondary thermal burns due to dehydration.[7][8] Dilute sulfuric acid is substantially less hazardous without the oxidative and dehydrating properties; though, it is handled with care for its acidity.

Sulfuric acid is a very important commodity chemical; a country's sulfuric acid production is a good indicator of its industrial strength.[9] Many methods for its production are known, including the contact process, the wet sulfuric acid process, and the lead chamber process.[10] Sulfuric acid is also a key substance in the chemical industry. It is most commonly used in fertilizer manufacture[11] but is also important in mineral processing, oil refining, wastewater processing, and chemical synthesis. It has a wide range of end applications, including in domestic acidic drain cleaners,[12] 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.

  1. ^ a b c Haynes, William M. (2014). CRC Handbook of Chemistry and Physics (95 ed.). CRC Press. pp. 4–92. ISBN 9781482208689. Retrieved 18 November 2018.
  2. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0577". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ Kemnitz, E.; Werner, C.; Trojanov, S. (15 November 1996). "Reinvestigation of Crystalline Sulfuric Acid and Oxonium Hydrogensulfate". Acta Crystallographica Section C Crystal Structure Communications. 52 (11): 2665–2668. Bibcode:1996AcCrC..52.2665K. doi:10.1107/S0108270196006749.
  4. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.
  5. ^ a b c "Sulfuric acid". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  6. ^ a b "Sulfuric acid safety data sheet" (PDF). arkema-inc.com. Archived from the original (PDF) on 17 June 2012. Clear to turbid oily odorless liquid, colorless to slightly yellow.
  7. ^ Cite error: The named reference OA was invoked but never defined (see the help page).
  8. ^ "BASF Chemical Emergency Medical Guidelines – Sulfuric acid (H2SO4)" (PDF). BASF Chemical Company. 2012. Archived from the original (PDF) on 14 June 2019. Retrieved 18 December 2014.
  9. ^ Chenier, Philip J. (1987). Survey of Industrial Chemistry. New York: John Wiley & Sons. pp. 45–57. ISBN 978-0-471-01077-7.
  10. ^ Hermann Müller "Sulfuric Acid and Sulfur Trioxide" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. 2000 doi:10.1002/14356007.a25_635
  11. ^ "Sulfuric acid". essentialchemicalindustry.org.
  12. ^ Cite error: The named reference dc was invoked but never defined (see the help page).