Formic acid, preparation, properties, chemical reactions

Formic acid, preparation, properties, and chemical reactions.



Formic acid (also methane acid) – an organic substance that belongs to the saturated monobasic carboxylic acids.


Formic acid, formula, specifications, characteristics

The physical properties of formic acid

Chemical properties of formic acid

Obtaining formic acid

Safety when handling formic acid. The Requirements Of GOST

The use of formic acid


Formic acid formula, features:

Formic acid (also methane acid) – an organic substance that belongs to the saturated monobasic carboxylic acids.

The chemical formula of formic acid CH₂Oco₂. The rational formula of formic acid HCOOH. Isomers has not.

The structure of the molecule of formic acid:

Formic acid (methane acid) is the simplest carboxylic acid, an ancestor of the class of carboxylic acids.

Formic acid is a colourless liquid, possessing a sharp-smelling odor.

Formic acid is a flammable liquid with a flashpoint of 60 °C, the ignition temperature of 504 °C.

An aqueous solution containing 85% formic acid, is also a combustible liquid with a flash point (open Cup) 71 °C, the ignition temperature of 83 °C.

If the temperature is above 69°C formic acid may form explosive mixture of vapor/air.

Soluble in acetone, benzene, glycerine, toluene. Mixed with water, diethyl ether, ethanol.

As a dietary Supplement, formic acid is registered as E236.

Formic acid got its name due to the fact that was first isolated in 1670, the English naturalist John Ray of red ants.

In nature, formic acid is contained in the venom of bees, nettles, needles, secretions jellyfish, fruits (apples, raspberries, strawberries, avocado, etc.).

The salts and anions of formic acid are referred to as formates.

The name formic acid English – formic acid.

Formic acid has a toxic effect dangerous to life and health (risk depends on the concentration), has corrosive properties.


The physical properties of formic acid:

Parameter name: Value:
Color without color
The smell the sharp smell
Taste sour
Aggregate state (at 25 °C and atmospheric pressure of 1 ATM.) liquid
Density (at 25 °C and atmospheric pressure of 1 ATM.) g/cm3 1,2196
Density (at 25 °C and atmospheric pressure of 1 ATM.) kg/m3 1219,6
Melting point, °C 8,25
Boiling point, °C 100,7
Triple point, °C When 8,25 2,2 kPa
Critical point, °C When 315 of 5.81 MPa
Flash point, °C 60
The auto-ignition temperature, °C 504
The dissociation constant 1,772⋅10-4
The dissociation constant of the acid 3,75
The concentration of explosive mixtures with air, % by volume from 18 to 57
Specific heat of combustion, MJ/kg 4,58
Molar mass, g/mol 46,03


Chemical properties of formic acid:

Formic acid, also acid properties, also shows some properties of the aldehydes, in particular, recovery.

It is characterized by the following chemical reactions:

1. the reaction of formic acid with alkalis:



During this reaction produces formate sodium (formate potassium) and water.

2. the reaction of formic acid with hydroxides:

HCOOH + 2Cu(OH)2 → CO2 + Cu2O + 3H2O.

During this reaction produces carbon dioxide, copper oxide and water.

3. the decomposition reaction of formic acid when heated:

HCOOH → CO + H2O (to, kat = H2SO4 (conc.) or P4O10).

When heated with strong vodootnimajushchih means, such as concentrated sulfuric acid or phosphorus oxide, decomposes into carbon monoxide (carbon monoxide) and water.

4. the reaction of formation of esters:

Formic acid reacts with alcohol, forming esters.


As a result of chemical reaction of formic acid with methanol (methyl alcohol) is formed methylformate (methyl ester of formic acid) and water.

5. the reaction with ammonia solution of silver oxide (reaction of silver mirror):

HCOOH + 2[AgNH3)2]HE→ 2Ag + (NH4)2CO3 + 2NH3 + H2O.

Since formic acid exhibits the properties of aldehydes, then it is characterized by the reaction of “silver mirror”. The reaction of “silver mirror” is a high-quality reaction on aldehydes. The reaction produced metallic silver. If the reaction is carried out in the vessel with a clean and smooth walls, the silver deposited on them in the form of a thin film, forming a mirror surface. In the presence of even the slightest contamination of the silver is excreted in the form of loose grey sediment.


Obtaining of formic acid:

Formic acid is obtained:

– oxidation of methanol (CH3OH);

– as a side product in the oxidation of butane to acetic acid production;

the reaction of carbon monoxide with sodium hydroxide (the main industrial method) in two stages.


In the first stage, get sodium formate, then it is treated with sulfuric acid;

– the decomposition glycerol esters of oxalic acid.


Safety when handling formic acid. Requirements GOST:

Formic acid is one of the substances 2-hazard class (GOST 12.1.007-76). Maximum permissible concentration in the air of the working zone of production areas (TLV) is 1 mg/m3 (see GOST 5848-73 Reagents. Formic acid. Specifications (with Amendments No. 1, 2, 3)).

When exceeding the maximum permissible concentration of a pair of formic acid are irritating to the mucous membrane of the upper respiratory tract and eyes; formic acid also causes burns to the skin.

Formic acid and its solutions are flammable liquids. All work with formic acid should be carried out away from fire.

All premises in which work is being carried out with formic acid, must be equipped with common supply and exhaust mechanical ventilation. Analysis of formic acid should be carried out in a fume hood laboratory.

When you work with it to apply individual means of protection. To prevent the entry of drugs into the body. First aid for burns – copious irrigation with water.


Application of formic acid:

Formic acid is used:

– in medicine,

in agriculture, as a preservative of hay and silage,

– in chemical industry as solvent,

– in the food industry as a preservative,

in the textile industry for dyeing wool,

– in beekeeping as a means to combat parasites.


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