LACTIC ACID - (50-21-5)


Name: lactic acid; 2-hydroxypropanoic acid
CAS Number: 50-21-5
Chemical Formula: C3H6O3 or CH3CH(OH)COOH
Molar Mass: 90.07794 g
Mass Percent: C 40.001 %; H 6.7137 %; O 53.285 % 
Isomers:  2-methoxyacetic acid  •  1,3-dihydroxyacetone



• "It occurs in sour milk from fermentation of lactose, and it is formed in muscles during the anaerobic cell respirationthat occurs during strenuous exercise. It is also formed during anaerobic muscle activity when glucose cannot be changed to pyruvic acid in glycolysis. It contributes to muscle fatigue. Lactic acid milk (buttermilk or acidophilus milk) helps to prevent the growth of putrefactive bacteria in the large intestine." 1


Double Bonds: 1
Triple Bonds: 0
Sigma Bonds: 11
Pi Bonds: 1
Total: 12
Carboxyl Groups: 1
Hydroxyl Groups: 1
Hybridization: double bonded carbon and oxygen are sp2; all other carbons and oxygens are sp3

For More Information


(1) - Taber's Cyclopedic Medical Dictionary, 18th ed.; F. A. David Company: Philadelphia, PA, 1997; p 22.