496 CONSIDERATION OF CARBON COMPOUNDS. 



soluble in 15 parts of boiling and 360 parts of cold water, soluble 

 with difficulty in alcohol; it fuses at 125.5 C. (258 F.), and vola- 

 tilizes at about 300 C. (572 F.), with partial decomposition. A 

 mixture of sul phonal with either wood charcoal or with potassium 

 cyanide evolves, on heating, the characteristic odor of mercaptan. It 

 is used as an hypnotic and soporific. 



Sulphonethylmethane, Trional, (?H'>C<c 2 2 H?S0 2 2 (Diethylsulphon- 



methyl-ethyl-methane), and Tetronal, c'EP^C^H-o^ (Diethylsulphon- 

 diethyl-methane), are both colorless solids, forming lustrous crystals, soluble in 

 hot water and in alcohol and ether. The therapeutic action of these bodies 

 is similar to that of sulphonal. 



45. MONOBASIC FATTY ACIDS. 



General constitution of organic acids. When hydroxyl, OH, 

 replaces hydrogen in hydrocarbons, alcohols are formed ; when the 

 univalent group, CO 2 H, known as carboxyl, replaces hydrogen in 

 hydrocarbons, acids are formed ; and all acids containing this radical 

 are termed carboxylic acids. Monatomic, diatomic, and triatomic 

 alcohols are formed by introducing hydroxyl once, twice, or three 

 times respectively into hydrocarbon molecules; monobasic, dibasic, 

 and tribasic acids are formed by substituting one, two, or three 

 hydrogen atoms by carboxyl. For instance : 



Hydrocarbons. Monobasic acids. Dibasic acids. 



CH 4 CH 3 C0 2 H CH 2 \C%H- 



Methane. Acetic acid. Malonic acid. 



C 2 H 6 C 2 H 5 CO 2 H ^ 2 ^*\CO 2 H* 



Ethane. Propionic acid. Succinic acid. 



As stated before, organic acids may also be considered as carbonic 



QUESTIONS. What is an aldehyde, and what are its relations to alcohols 

 and acids ? Give composition, mode of manufacture, and properties of form- 

 aldehyde. Explain the action of chlorine upon alcohol. Give the compo- 

 sition and properties of chloral and hydrated chloral. What decomposition 

 takes place when alkalies act upon chloral ? Under what conditions is acro- 

 lein formed and what are its properties ? Give the general composition of 

 ketones and a general method of obtaining them. How is acetone prepared? 

 Which compounds are called mercaptans, and how are they converted into 

 sulphonic acids ? Give method for preparing sulphonal, and state its prop- 

 erties. 



