formic acid formic acid formic acid skeletal structure of formic acid 3d model of formic acid names preferred iupac name formic acid systematic iupac name methanoic acid other names isocarbonous acidcarbonous acidformylic acidmethylic acidhydrogencarboxylic acidhydroxy(oxo)methanemetacarbonoic acidoxocarbinic acidoxomethanolhydroxymethylene oxideant acid identifiers cas number 64-18-6 y 3d model (jsmol) interactive image beilstein reference 1209246 chebi chebi:30751 y chembl chembl116736 y chemspider 278 y drugbank db01942 y echa infocard 100.000.527 ec number 200-579-1 e number e236 (preservatives) gmelin reference 1008 kegg c00058 y pubchem cid 284 rtecs number lq4900000 unii 0yiw783rg1 y comptox dashboard (epa) dtxsid2024115 inchi inchi=1s/hcooh/c2-1-3/h1h,(h,2,3) nkey: bdagihxwwsansr-uhfffaoysa-n yinchi=1/hcooh/c2-1-3/h1h,(h,2,3)key: bdagihxwwsansr-uhfffaoyat smiles o=co properties chemical formula ch2o2 molar mass 46.025 g·mol−1 appearance colorless fuming liquid odor pungent, penetrating density 1.220 g/ml melting point 8.4 °c (47.1 °f; 281.5 k) boiling point 100.8 °c (213.4 °f; 373.9 k) solubility in water miscible solubility miscible with ether, acetone, ethyl acetate, glycerol, methanol, ethanol partially soluble in benzene, toluene, xylenes log p −0.54 vapor pressure 35 mmhg (20 °c) acidity (pka) 3.745 conjugate base formate magnetic susceptibility (χ) −19.90×10−6 cm3/mol refractive index (nd) 1.3714 (20 °c) viscosity 1.57 cp at 268 °c structure molecular shape planar dipole moment 1.41 d (gas) thermochemistry std molarentropy (s⦵298) 131.8 j/mol k std enthalpy offormation (δfh⦵298) −425.0 kj/mol std enthalpy ofcombustion (δch⦵298) −254.6 kj/mol pharmacology atcvet code qp53ag01 (who) hazards occupational safety and health (ohs/osh): main hazards corrosive; irritant;sensitizer ghs labelling: pictograms signal word danger hazard statements h314 precautionary statements p260, p264, p280, p301+p330+p331, p303+p361+p353, p304+p340, p305+p351+p338, p310, p321, p363, p405, p501 nfpa 704 (fire diamond) 3 2 0 flash point 69 °c (156 °f; 342 k) autoignitiontemperature 601 °c (1,114 °f; 874 k) explosive limits 14–34% 18–57% (90% solution) lethal dose or concentration (ld, lc): ld50 (median dose) 700 mg/kg (mouse, oral), 1100 mg/kg (rat, oral), 4000 mg/kg (dog, oral) lc50 (median concentration) 7853 ppm (rat, 15 min)3246 ppm (mouse, 15 min) niosh (us health exposure limits): pel (permissible) twa 5 ppm (9 mg/m3) rel (recommended) twa 5 ppm (9 mg/m3) idlh (immediate danger) 30 ppm safety data sheet (sds) msds from jt baker related compounds related carboxylic acids acetic acidpropionic acid related compounds formaldehydemethanol supplementary data page formic acid (data page) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references "ant acid" redirects here. for substances that neutralize stomach acidity, see antacid. formic acid (from latin formica 'ant'), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula hcooh and structure h−c(=o)−o−h. it is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. esters, salts and the anion derived from formic acid are called formates. industrially, formic acid is produced from methanol. natural occurrence in nature, formic acid is found in most ants and in stingless bees of the genus oxytrigona. wood ants from the genus formica can spray formic acid on their prey or to defend the nest. the puss moth caterpillar (cerura vinula) will spray it as well when threatened by predators. it is also found in the trichomes of stinging nettle (urtica dioica). apart from that, this acid is incorporated in many fruits such as pineapple (0.21mg per 100g), apple (2mg per 100g) and kiwi (1mg per 100g), as well as in many vegetables, namely onion (45mg per 100g), eggplant (1.34 mg per 100g) and, in extremely low concentrations, cucumber (0.11mg per 100g). formic acid is a naturally occurring component of the atmosphere primarily due to forest emissions. history some alchemists and naturalists were aware that ant hills give off an acidic vapor as early as the 15th century. the first person to describe the isolation of this substance (by the distillation of large numbers of ants) was the english naturalist john ray, in 1671. ants secrete the formic acid for attack and defense purposes. formic acid was first synthesized from hydrocyanic acid by the french chemist joseph gay-lussac. in 1855, another french chemist, marcellin berthelot, developed a synthesis from carbon monoxide similar to the process used today. formic acid was long considered a chemical compound of only minor interest in the chemical industry. in the late 1960s, however, significant quantities became available as a byproduct of acetic acid production. it now finds increasing use as a preservative and antibacterial in livestock feed. properties cyclic dimer of formic acid; dashed green lines represent hydrogen bonds formic acid is a colorless liquid having a pungent, penetrating odor at room temperature, comparable to the related acetic acid. formic acid is about ten times stronger than acetic acid. it is miscible with water and most polar organic solvents, and is somewhat soluble in hydrocarbons. in hydrocarbons and in the vapor phase, it consists of hydrogen-bonded dimers rather than individual molecules. owing to its tendency to hydrogen-bond, gaseous formic acid does not obey the ideal gas law. solid formic acid, which can exist in either of two polymorphs, consists of an effectively endless network of hydrogen-bonded formic acid molecules. formic acid forms a high-boiling azeotrope with water (22.4%). liquid formic acid tends to supercool. chemical reactions decomposition formic acid readily decomposes by dehydration in the presence of concentrated sulfuric acid to form carbon monoxide and water: hco2h → h2o + co treatment of formic acid with sulfuric acid is a convenient laboratory source of co. in the presence of platinum, it decomposes with a release of hydrogen and carbon dioxide. hco2h → h2 + co2 soluble ruthenium catalysts are also effective. carbon monoxide free hydrogen has been generated in a very wide pressure range (1–600 bar). reactant formic acid shares most of the chemical properties of other carboxylic acids. because of its high acidity, solutions in alcohols form esters spontaneously. formic acid shares some of the reducing properties of aldehydes, reducing solutions of metal oxides to their respective metal. formic acid is a source for a formyl group for example in the formylation of methylaniline to n-methylformanilide in toluene. in synthetic organic chemistry, formic acid is often used as a source of hydride ion, as in the eschweiler-clarke reaction: the eschweiler–clark reaction it is used as a source of hydrogen in transfer hydrogenation, as in the leuckart reaction to make amines, and (in aqueous solution or in its azeotrope with triethylamine) for hydrogenation of ketones. addition to alkenes formic acid is unique among the carboxylic acids in its ability to participate in addition reactions with alkenes. formic acids and alkenes readily react to form formate esters. in the presence of certain acids, including sulfuric and hydrofluoric acids, however, a variant of the koch reaction occurs instead, and formic acid adds to the alkene to produce a larger carboxylic acid. formic acid anhydride an unstable formic anhydride, h(c=o)−o−(c=o)h, can be obtained by dehydration of formic acid with n,n′-dicyclohexylcarbodiimide in ether at low temperature. production in 2009, the worldwide capacity for producing formic acid was 720 thousand tonnes (1.6 billion pounds) per year, roughly equally divided between europe (350 thousand tonnes or 770 million pounds, mainly in germany) and asia (370 thousand tonnes or 820 million pounds, mainly in china) while production was below 1 thousand tonnes or 2.2 million pounds per year in all other continents. it is commercially available in solutions of various concentrations between 85 and 99 w/w %. as of 2009, the largest producers are basf, eastman chemical company, lc industrial, and feicheng acid chemicals, with the largest production facilities in ludwigshafen (200 thousand tonnes or 440 million pounds per year, basf, germany), oulu (105 thousand tonnes or 230 million pounds, eastman, finland), nakhon pathom (n/a, lc industrial), and feicheng (100 thousand tonnes or 220 million pounds, feicheng, china). 2010 prices ranged from around €650/tonne (equivalent to around $800/tonne) in western europe to $1250/tonne in the united states. from methyl formate and formamide when methanol and carbon monoxide are combined in the presence of a strong base, the result is methyl formate, according to the chemical equation: ch3oh + co → hco2ch3 in industry, this reaction is performed in the liquid phase at elevated pressure. typical reaction conditions are 80 °c and 40 atm. the most widely used base is sodium methoxide. hydrolysis of the methyl formate produces formic acid: hco2ch3 + h2o → hcooh + ch3oh efficient hydrolysis of methyl formate requires a large excess of water. some routes proceed indirectly by first treating the methyl formate with ammonia to give formamide, which is then hydrolyzed with sulfuric acid: hco2ch3 + nh3 → hc(o)nh2 + ch3oh 2 hc(o)nh2 + 2h2o + h2so4 → 2hco2h + (nh4)2so4 a disadvantage of this approach is the need to dispose of the ammonium sulfate byproduct. this problem has led some manufacturers to develop energy-efficient methods of separating formic acid from the excess water used in direct hydrolysis. in one of these processes, used by basf, the formic acid is removed from the water by liquid-liquid extraction with an organic base. by-product of acetic acid production a significant amount of formic acid is produced as a byproduct in the manufacture of other chemicals. at one time, acetic acid was produced on a large scale by oxidation of alkanes, by a process that cogenerates significant formic acid. this oxidative route to acetic acid has declined in importance so that the aforementioned dedicated routes to formic acid have become more important. hydrogenation of carbon dioxide the catalytic hydrogenation of co2 to formic acid has long been studied. this reaction can be conducted homogeneously. oxidation of biomass formic acid can also be obtained by aqueous catalytic partial oxidation of wet biomass by the oxfa process. a keggin-type polyoxometalate (h5pv2mo10o40) is used as the homogeneous catalyst to convert sugars, wood, waste paper, or cyanobacteria to formic acid and co2 as the sole byproduct. yields of up to 53% formic acid can be achieved. laboratory methods in the laboratory, formic acid can be obtained by heating oxalic acid in glycerol and extraction by steam distillation. glycerol acts as a catalyst, as the reaction proceeds through a glyceryl oxalate intermediate. if the reaction mixture is heated to higher temperatures, allyl alcohol results. the net reaction is thus: c2o4h2 → hco2h + co2 another illustrative method involves the reaction between lead formate and hydrogen sulfide, driven by the formation of lead sulfide. pb(hcoo)2 + h2s → 2hcooh + pbs electrochemical production it has been reported that formate can be formed by the electrochemical reduction of co2 (in the form of bicarbonate) at a lead cathode at ph 8.6: hco−3 + h2o + 2e− → hco−2 + 2oh− or co2 + h2o + 2e− → hco−2 + oh− if the feed is co2 and oxygen is evolved at the anode, the total reaction is: co2 + oh− → hco−2 + 1/2 o2 artificial photosynthesis in august 2020, researchers at cambridge university announced a stand-alone advanced 'photosheet' technology that converts sunlight, carbon dioxide and water into oxygen and formic acid with no other inputs. biosynthesis formic acid is named after ants which have high concentrations of the compound in their venom. in ants, formic acid is derived from serine through a 5,10-methenyltetrahydrofolate intermediate. the conjugate base of formic acid, formate, also occurs widely in nature. an assay for formic acid in body fluids, designed for determination of formate after methanol poisoning, is based on the reaction of formate with bacterial formate dehydrogenase. uses agriculture a major use of formic acid is as preservative and antibacterial agent in livestock feed. in europe, it is applied on silage, including fresh hay, to promote the fermentation of lactic acid and to suppress the formation of butyric acid; it also allows fermentation to occur quickly, and at a lower temperature, reducing the loss of nutritional value. formic acid arrests certain decay processes and causes the feed to retain its nutritive value longer, and so it is widely used to preserve winter feed for cattle. in the poultry industry, it is sometimes added to feed to kill e. coli bacteria. use as a preservative for silage and (other) animal feed constituted 30% of the global consumption in 2009. beekeepers use formic acid as a miticide against the tracheal mite (acarapis woodi) and the varroa destructor mite and varroa jacobsoni mite. energy formic acid can be used in a fuel cell (it can be used directly