ETHERS AND ESTERS. 519 



Hydroxides. Oxides. Acids. 



KOH = g\0 K 2 = \0 HN0 3 = N ^)0 KNO 3 - N( j>O 

 Potassium hydroxide. Potassium oxide. Nitric acid. Potassium nitrate. 



Ethyl alcohol. Ethyl ether. Acetic acid. Ethyl acetate, or 



acetic ether. 



ET R H R* 



Alcohol. Ether. Acid. Ester. 



It is not necessary that the two hydrocarbon residues in au ether 

 should be alike, as in the above ethyl ether, but they may be different, 

 in which case the ethers are termed mixed ethers. For instance : 



CH 3 .C 2 H 5 = g H\o q,H,AH u .O = 



Methyl-ethyl ether. Propyl-amyl ether. 



In diatomic or triatomic alcohols, or in dibasic or tribasic acids, 

 containing more than one atom of hydrogen derived from hydroxyl 

 or carboxyl, these hydrogen atoms may be replaced by various other 

 univalent, bivalent, or trivalent residues. This fact shows that the 

 number of ethers or esters which are capable of being formed is very 

 large. 



Formation of ethers. Ethers may be formed by the action of 

 the chloride or iodide of a hydrocarbon residue upon an alcohol, in 

 which the hydroxyl hydrogen has been replaced by a metal. For 

 instance : 



C <> + QftI = %!;> + Nal. 

 Sodium ethylate. Ethyl iodide. Ethyl ether. Sodium iodide. 



Sodium Methyl Ethyl-methyl Sodium 



ethylate. iodide. ether. iodide. 



Ethers are also formed by the action of sulphuric acid upon alco- 

 hols ; the sulphuric acid removing water in this case, thus : 



2(C 2 H 5 OH) : 2 H 5 + 



Ethyl alcohol. Ethyl ether. Water. 



Esters are formed by the combination of acids with alcohols and 

 elimination of water. (Presence of sulphuric acid facilitates this 

 action.) 



+ C 2 H S 0\ = 



Ethyl alcohol. Acetic acid. Ethyl acetate. Water. 



