Citric acid

  • citric acid
    zitronensäure - citric acid.svg
    citric-acid-3d-balls.png
    zitronensäure kristallzucht.jpg
    names
    iupac name
    citric acid[1]
    systematic iupac name
    2-hydroxypropane-1,2,3-tricarboxylic acid
    identifiers
    cas number
    • 77-92-9 ☑y
    3d model (jsmol)
    • interactive image
    chebi
    • chebi:30769 ☑y
    chembl
    • chembl1261 ☑y
    chemspider
    • 305 ☑y
    drugbank
    • db04272 ☑y
    echa infocard 100.000.973
    ec number
    • 201-069-1
    e number e330 (antioxidants, ...)
    iuphar/bps
    • 2478
    kegg
    • d00037 ☑y
    pubchem cid
    • 311
    • 22230 (monohydrate)
    rtecs number
    • ge7350000
    unii
    • xf417d3psl ☑y
    comptox dashboard (epa)
    • dtxsid3020332 edit this at wikidata
    properties
    chemical formula
    c6h8o7
    molar mass 192.123 g/mol (anhydrous), 210.14 g/mol (monohydrate)[2]
    appearance crystalline white solid
    odor odorless
    density 1.665 g/cm3 (anhydrous)
    1.542 g/cm3 (18 °c, monohydrate)
    melting point 156 °c (313 °f; 429 k)
    boiling point 310 °c (590 °f; 583 k) decomposes from 175 °c[3]
    solubility in water
    54% w/w (10 °c)
    59.2% w/w (20 °c)
    64.3% w/w (30 °c)
    68.6% w/w (40 °c)
    70.9% w/w (50 °c)
    73.5% w/w (60 °c)
    76.2% w/w (70 °c)
    78.8% w/w (80 °c)
    81.4% w/w (90 °c)
    84% w/w (100 °c)[4]
    solubility soluble in acetone, alcohol, ether, ethyl acetate, dmso
    insoluble in 6, chcl3, cs2, toluene[3]
    solubility in ethanol 62 g/100 g (25 °c)[3]
    solubility in amyl acetate 4.41 g/100 g (25 °c)[3]
    solubility in diethyl ether 1.05 g/100 g (25 °c)[3]
    solubility in 1,4-dioxane 35.9 g/100 g (25 °c)[3]
    log p −1.64
    acidity (pka) pka1 = 3.13[5]
    pka2 = 4.76[5]
    pka3 = 6.39,[6] 6.40[7]
    refractive index (nd)
    1.493–1.509 (20 °c)[4]
    1.46 (150 °c)[3]
    viscosity 6.5 cp (50% aq. sol.)[4]
    structure
    crystal structure
    monoclinic
    thermochemistry
    heat capacity (c)
    226.51 j/(mol·k) (26.85 °c)[8]
    std molar
    entropy
    (so298)
    252.1 j/(mol·k)[8]
    std enthalpy of
    formation
    fh298)
    −1543.8 kj/mol[4]
    std enthalpy of
    combustion
    ch298)
    −1960.6 kj/mol[8]
    −1972.34 kj/mol (monohydrate)[4]
    pharmacology
    atc code
    who)
    hazards
    main hazards skin and eye irritant
    safety data sheet hmdb
    ghs pictograms ghs07: harmful[5]
    ghs signal word warning
    ghs hazard statements
    h319[5]
    ghs precautionary statements
    p305+351+338[5]
    nfpa 704 (fire diamond)
    nfpa 704 four-colored diamond
    0
    1
    0
    flash point 155 °c (311 °f; 428 k)
    autoignition
    temperature
    345 °c (653 °f; 618 k)
    explosive limits 8%[5]
    lethal dose or concentration (ld, lc):
    ld50 (median dose)
    3000 mg/kg (rats, oral)
    except where otherwise noted, data are given for materials in their standard state (at 25 °c [77 °f], 100 kpa).
    ☒n verify (what is ☑y☒n ?)
    infobox references

    citric acid is a weak organic acid that has the chemical formula c
    6
    h
    8
    o
    7
    . it occurs naturally in citrus fruits. in biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.

    more than two million tons of citric acid are manufactured every year. it is used widely as an acidifier, as a flavoring and a chelating agent.[9]

    a citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. an example of the former, a salt is trisodium citrate; an ester is triethyl citrate. when part of a salt, the formula of the citrate ion is written as c
    6
    h
    5
    o3−
    7
    or c
    3
    h
    5
    o(coo)3−
    3
    .

  • natural occurrence and industrial production
  • chemical characteristics
  • biochemistry
  • applications
  • synthesize solid materials from small molecules
  • safety
  • compendial status
  • see also
  • references

Citric acid
Zitronensäure - Citric acid.svg
Citric-acid-3D-balls.png
Zitronensäure Kristallzucht.jpg
Names
IUPAC name
Citric acid[1]
Systematic IUPAC name
2-Hydroxypropane-1,2,3-tricarboxylic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.973
EC Number
  • 201-069-1
E number E330 (antioxidants, ...)
KEGG
RTECS number
  • GE7350000
UNII
Properties
C6H8O7
Molar mass 192.123 g/mol (anhydrous), 210.14 g/mol (monohydrate)[2]
Appearance Crystalline white solid
Odor Odorless
Density 1.665 g/cm3 (anhydrous)
1.542 g/cm3 (18 °C, monohydrate)
Melting point 156 °C (313 °F; 429 K)
Boiling point 310 °C (590 °F; 583 K) decomposes from 175 °C[3]
54% w/w (10 °C)
59.2% w/w (20 °C)
64.3% w/w (30 °C)
68.6% w/w (40 °C)
70.9% w/w (50 °C)
73.5% w/w (60 °C)
76.2% w/w (70 °C)
78.8% w/w (80 °C)
81.4% w/w (90 °C)
84% w/w (100 °C)[4]
Solubility Soluble in acetone, alcohol, ether, ethyl acetate, DMSO
Insoluble in 6, CHCl3, CS2, toluene[3]
Solubility in ethanol 62 g/100 g (25 °C)[3]
Solubility in amyl acetate 4.41 g/100 g (25 °C)[3]
Solubility in diethyl ether 1.05 g/100 g (25 °C)[3]
Solubility in 1,4-Dioxane 35.9 g/100 g (25 °C)[3]
log P −1.64
Acidity (pKa) pKa1 = 3.13[5]
pKa2 = 4.76[5]
pKa3 = 6.39,[6] 6.40[7]
1.493–1.509 (20 °C)[4]
1.46 (150 °C)[3]
Viscosity 6.5 cP (50% aq. sol.)[4]
Structure
Monoclinic
Thermochemistry
226.51 J/(mol·K) (26.85 °C)[8]
252.1 J/(mol·K)[8]
−1543.8 kJ/mol[4]
−1960.6 kJ/mol[8]
−1972.34 kJ/mol (monohydrate)[4]
Pharmacology
WHO)
Hazards
Main hazards Skin and eye irritant
Safety data sheet HMDB
GHS pictograms GHS07: Harmful[5]
GHS Signal word Warning
H319[5]
P305+351+338[5]
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
0
Flash point 155 °C (311 °F; 428 K)
345 °C (653 °F; 618 K)
Explosive limits 8%[5]
Lethal dose or concentration (LD, LC):
3000 mg/kg (rats, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is ☑Y☒N ?)
Infobox references

Citric acid is a weak organic acid that has the chemical formula C
6
H
8
O
7
. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.

More than two million tons of citric acid are manufactured every year. It is used widely as an acidifier, as a flavoring and a chelating agent.[9]

A citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When part of a salt, the formula of the citrate ion is written as C
6
H
5
O3−
7
or C
3
H
5
O(COO)3−
3
.