﻿ACTION OF SODIUM ON ACETONE. 69 



in the insoluble precipitate and in the soluble portion. It has in the 

 past been expressly stated that sodium-acetone, when prepared with all 

 precautions, is white and that reddening is due to decomposition in the 

 air or by reason if moisture. 



EXPERIMENTAL. 



Sodium acetone is a very delicate substance. When properly prepared 

 and when air and moisture are rigidly excluded it is a snow-white, floc- 

 culent solid. On exposure to the air and to moisture it becomes pink, 

 then red and brown, an oil at the same time separating, the color changes 

 representing the formation of sodium hydroxide and condensation prod- 

 ucts of acetone. Of course, as had previously been shown, sodium 

 acetone also contains sodium isopropylalcoholate, and some sodium pina- 

 konate and, in the reactions performed under ether, some sodium ethylate. 

 All ether which we used in these experiments was repeatedly dried and 

 distilled from sodium wire until this wire would remain perfectly bright 

 under the solvent. The acetone was from the bisulphite compound and 

 was dried four times over phosphorus pentoxide, each time being poured 

 off and distilled. Dry hydrogen was run through the acetone for some 

 hours to remove any air or carbon dioxide and it was then kept over fused 

 sodium sulphate and protected from moisture and carbon dioxide by tubes 

 containing phosphorus pentoxide and soda lime. 



Experiment 1. — The apparatus used was that described by Freer. 7 

 About 1.6 grams of sodium, cut under coal oil and then washed with 

 absolute ether, were quickly squeezed as a very fine wire into about 50 

 cubic centimeters of absolute ether in the reaction flask, and the apparatus 

 quickly closed. Dry and pure hydrogen was now run through the ap- 

 paratus for three hours. The reaction flask was then surrounded by ice 

 and 10 cubic centimeters of acetone, dissolved in 50 cubic centimeters 

 of absolute ether, gradually added through a dropping funnel. Bubbles 

 of hydrogen were given off and the separation of a white, gelatinous 

 precipitate soon commenced. When all of the sodium had disappeared, 

 the ether and precipitate were sucked into a filtering tube, the latter 

 washed eight times with absolute ether, using 50 cubic centimeters each 

 time and always sucking as dry as possible. The precipitate was then 

 dried to constant weight in a current of hydrogen, weighed, and decom- 

 posed with dilute, ice-cold sulphuric acid. Only a minimal amount of 

 acetone-condensation products was obtained, as the sodium salt was prac- 

 tically completely soluble in water. In no instance, if the sodium deriv- 

 ative had been properly prepared, was there more than a drop or two 

 of insoluble oil. When small amounts of air or moisture gain access to 

 the sodium derivative, or when the decomposition by acids is not carefully 



7 Am. Chem. Journ. (1893), 15, 588. 



