FUNDAMENTAL CONCEPTIONS 217 



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3CH 2 - CH 2 + 6H - OH + 2KMn04 -> OHOH 



3CH 2 - CH 2 + 2MnO 2 + 2KOH + 2H 2 O.' 



Analogous results would naturally be expected in the case of ail 

 the homologous primary and secondary alcohols. Now a primary 

 alcohol invariably first gives by oxidation with potassium permangan- 

 ate or other oxidizing agents the corresponding fatty acid; glycols or 

 their oxidation products have never been observed in such cases. The 

 fact that ethylalcohol gives glyoxal, glyoxylic and oxalic acids with 

 nitric acid, is no exception to this rule because these substances result 

 from the hydrolysis and oxidation of isonitrosoacetaldehyde which 

 is formed by the action of nitrous acid on acetaldehyde as follows: 



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 H - CH 2 CHO + - NOH -> HO - N - OH -> HON =CHCH :O + H 2 O. 



I 

 CH 2 -CH:0 



The behavior of aldehydes and of primary alcohols towards aqueous 

 or solid caustic potash also leads to the conclusion that only alkylidene 

 dissociation occurs. Ethylalcohol gives at 250, with an excess of 

 caustic potash, hydrogen and potassium acetate quantitatively, 



H 

 CH 3 CH / + 2KO - H - CH 3 CH / + 3KOH - 



OK 



CH 3 



H(OK) 2 + 2H-+KOH-^ ^C/ + 2H-OK + H 2 - 



KO 

 CH 3 



KO 



If any of the potassium ethylate, which is first formed, were disso- 

 ciated into ethylene and caustic potash, 



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CH 3 .CH 2 OK^tCH 2 - CH 2 + HOK, 



the olefine must naturally give, besides hydrogen, ethylene glycol, 



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 CH 2 .CH 2 + 2HOK->KOCH 2 -CH 2 OK + H 2 , or its decomposition pro- 



ducts; these are, however, not formed. The reaction with potash 

 lime and primary alcohols is so delicate and accurate that it has 

 been suggested by Hell as a means of determining the molecular 

 weight of an unknown primary alcohol. 



