hrh 



Q.nr 



348 



-^2. Hydroxyl Derivatives (Alcohols}. Water acts slowly 

 upon methyl chloride, according to the equation : 



| CH 3 C1 + H 2 O ^i HC1 +_CH.,OH fmethvl alcohol) . 



.e reaction is reversible and incomplete, but can be accelerated 

 and carried to completion by addition of a base, which removes 

 the HC1 as fast as it is formed. Ethyl chloride C 2 H 5 C1 gives 

 ethyl alcohol C 2 H 5 OH. 



Although containing the radical OH, the alcohols are not ion- 

 ized in solution, and are therefore not bases. They are extensively 

 used as solvents for other organic substances (see also p. 418). 



3. Oxygen Derivatives (Ethers'). When ethyl alcohol and 

 ^concentrated sulphuric acid are heated to 140, water and ether 



(C2H 5 ) 2 O distil off. The action occurs in two stages: 



(1) C 2 H 5 OH + H 2 SO 4 -> H 2 O + C 2 H 5 .HSO 4 



(2) C 2 H 5 .HS0 4 + C 2 H 5 OH - H 2 SO 4 + (C 2 H 5 ) 2 O. 



Ether (C 2 H 5 ) 2 O is a very volatile and inflammable liquid, used 

 as an anaesthetic and as a solvent for resins, fats and oils. 



4. Aldehydes. By fractional combustion of methyl alcohol 

 (passage of a heated mixture of alcohol vapor and air over a metal 

 catalyst), formaldehyde H.CHO is obtained: 



2CH 3 .OH + 2 - 2CH 2 + 2H 2 O. 



Formaldehyde is a gas. Its solution in water (formalin) 

 is employed as an antiseptic and disinfectant. Its property of 

 hardening gelatins makes it valuable in the leather industry 

 and in the manufacture of artificial silk. It is also used in making 

 dyes and in the production of bakelite (p. 481). The correspond- 

 ing derivative of ethyl alcohol is acetaldehyde CH 3 .CHO. The 

 group .CHO is characteristic of aldehydes. 



5. Acids. By further partial oxidation, alcohols or aldehydes 

 give members of the fatty acid series. Thus ethyl alcohol can 



