Citric acid

Citric acid is a weak organic acid. It can be found in citrus fruits. It is used by organisms for Krebs cycle. It acts like a preservative when added to food. It is also used to add a sour (acidic) taste to foods and soft drinks. In the European Union it is known as E 330, as a food additive.

Carl Wilhelm Scheele was the first who could extract citric acid from lemons, in 1782. The substance was probably known to alchemists, perhaps with a different name. The Arabian alchemist Geber is said to have discovered citric acid in the 9th century. Citric Acid contains 6 Carbon atoms, 8 Hydrogen atoms and 7 Oxygen atoms. Its chemical formula is C6H8O7.

 Main uses 
 As a water softener
 It is often used in detergents, to avoid the smell of acid, esp. Acetic acid
 As a preserving agent
 Citric acid and its salts prevent blood clotting. Blood donations are kept liquid using citric acid.

References

 Other websites 
 Citric acid analysis - free spreadsheet for titration of acids and pH calculation

Category:Carboxylic acids
Category:Citrus