What is the structure of butanoic acid

Butyric acid C.3H7COOH
Clear, oily liquid
Intestines, sweaty feet, sour milk
molar mass 88.106 g / mol

AGW not specified
pKs-Value  +4,83
density 0.9528 g / cm3   
Melting point −5.12 ° C
boiling point +163.7 ° C
Water solubility fully miscible
Explosion limit 2.0 to 10% by volume (air)
Flash point +72 ° C
Ignition point +443 ° C

GHS 05
GHS 07
Hazard classes + category 
Acute toxicity oral 4
Skin corrosion 1B
Serious eye damage 1
(Gradation for dilutions)
HP rates (see also note)  
H 302,314
P 260, 280.1-3.7, 303 + 361 + 353, 304 + 340 + 310, 305 + 351 + 338 + 310
disposal G 1
print a labelGerman designation 
Synonyms (German)
English designation 
CAS 107-92-6Butyric acid 
Butanoic acid
Butyric acid 
Butanoic acid
Notes for schools: Butyric acid is a corrosive substance. It is mandatory to wear protective goggles and protective gloves. Ensure good ventilation or work in the fume cupboard. A Teflon cap largely prevents evaporation from the bottle. Working with butyric acid is only recommended for experienced internship participants, as the substance smells extremely penetrating.

Butyric acid smells extremely unpleasant and disgusting like "vomit". The vapors irritate the eyes and the respiratory tract. Butyric acid is produced when butter turns rancid. It dissolves very well in water and also in ethyl alcohol, diethyl ether and glycerine.

Compared to formic acid and acetic acid, carboxylic acid is a weaker acid. Iron, zinc, magnesium and other base metals dissolve very slowly with the evolution of hydrogen. The salts of butyric acid, the butyrates, are formed, which also smell of butyric acid when wet:  
Magnesium + butyric acid Magnesium butyrate + hydrogen
Butyric acid + ethanol Butyric acid ethyl ester + water
Amazingly, the result is an ester with a nice smelling pineapple scent, which is used in the perfume industry and for making liqueurs.
It is produced by the oxidation of butanol and air with the aid of suitable catalysts or by an oxo synthesis from propene and carbon monoxide. The fermentation of carbohydrates by Clostridium bacteria is also important:
C.6H12O6  C.3H7COOH + 2 CO2 + 2 H.2
Butyric acid is used to manufacture butyric acid esters, medicines, pesticides and cellulose butyrate, a weather-resistant and impact-resistant plastic.