|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
anhydride
anhydride [Gr.,=without water], chemical compound formed by removing water, H 2 O, from another compound; the anhydride can also react with water to form the original compound. An acid anhydride reacts with water to form an acid; e.g., sulfur trioxide, SO 3 , reacts with water to form sulfuric acid, H 2 SO 4 . A basic anhydride reacts with water to form a base; e.g., calcium oxide, CaO, reacts with water to form calcium hydroxide, Ca(OH) 2 . Anhydrides of organic acids have many uses. They react with alcohols to form esters; e.g., acetic anhydride, (CH 3 CO) 2 O, reacts with ethanol, C 2 H 5 OH, to form ethyl acetate, CH 3 COOC 2 H 5 , a useful solvent. They also react with ammonia and primary or secondary amines to form amides. Other important acid anhydrides include maleic anhydride and phthalic anhydride. |
|
|
Cite this article
"anhydride." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "anhydride." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-anhydrid.html "anhydride." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-anhydrid.html |
|
creatinine
creatinine Formed non‐enzymically from creatine (chemically the anhydride of creatine). Urinary excretion of creatinine is relatively constant from day to day, and reflects mainly the amount of muscle tissue in the body. Therefore the amounts of various components of urine are often expressed relative to creatinine.
|
|
|
Cite this article
DAVID A. BENDER. "creatinine." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. DAVID A. BENDER. "creatinine." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-creatinine.html DAVID A. BENDER. "creatinine." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-creatinine.html |
|