256 CONSIDERATION OF CARBON COMPOUNDS. 



The additional quantity of oxygen thus introduced into the 

 molecules, renders them highly combustible or even explosive. 



Action of dehydrating agents. Substances having a great 

 affinity for water, such as strong sulphuric acid, phosphoric 

 oxide, and others, act upon many organic substances by remov- 

 ing from them the elements of hydrogen and oxygen, and com- 

 bining with the water formed, while, at the same time, frequently 

 dark or even black compounds are formed, which consist mainly 

 of carbon. The black color imparted to sulphuric acid by 

 organic matter depends on this action. 



Action of alkalies. The hydrates of potassium and sodium act 

 in various ways on organic substances. 



In some cases direct combination takes place : 



CO + KHO = KCH0 2 . 



Carbonic Potassium Potassium 



oxide. hydrate. formate. 



Salts are formed : 



C 2 H 4 O 2 + NaHO = NaC 2 H 3 O 2 + H 2 O. 



Acetic Sodium Sodium Water, 



acid. hydrate. acetate. 



Fats are decomposed with the formation of soap : 



C 3 H 5 3(C 18 H 33 2 ) + 3NaHO , . C 3 H 5 3HO + 3(NaC 18 H 33 2 ). 



Oleate of glyceril. Sodium Glycerine. Sodium oleate. 



hydrate. 



Oxidation takes place, whilst hydrogen is liberated: 

 C 2 H 6 + KHO i KC 2 H 3 2 + 4H. 



Ethyl Potassium Potassium Hydrogen, 



alcohol. hydrate. acetate. 



From compounds containing nitrogen, ammonia is evolved 

 NH 2 C 2 H 3 O + KHO = KC 2 H 3 O 2 + NH 3 . 



Acetamide. Potassium Potassium Ammonia, 



hydrate. acetate. 



