300 Mixter — Products of the Explosion of Acetylene. 



Experiment 37. — Gas, 98 per cent of acetylene ; pressure, 

 1289 mm ; temperature, 12° ; electrodes, 2 mm apart. The gas 

 was sparked repeatedly for several seconds. Carbon separated 

 about the electrodes, but there was no explosion and the gas 

 after the sparking was found to contain 98 per cent of acety- 

 lene. 



Experiment 38. — Gas, 98 per cent of acetylene ; pressure, 

 1312 mra ; temperature, 15°. The electrodes were 3 mm apart. 

 There was no explosion and no change in pressure during 

 the sparking. 



Experiment 39. — Gas, 96 per cent of acetylene ; pressure, 

 ltt72 mm ; temperature, 14°. The pressure after the explosion 

 at 14° was 1425 mm , showing a condensation of 3"2 per cent. 

 Two determinations of acetylene in the residual gas gave 3*4 

 and 3*3 per cent. 



Experiment 4-0. — Gas, 98 per cent of acetylene ; pressure, 

 5*1 atmospheres, which was the same after the explosion when 

 the bomb had attained the temperature of the water in the 

 tank in which it was immersed. The gas tested was taken 

 before the pressure in the bomb had fallen below 4 atmos- 

 pheres. Three tests yielded 2'3, 2"4 and 2*4 per cent of acety- 

 lene. The carbon nearly filled the bomb. 



The nitrogen used in subsequent experiments was prepared 

 from sodium nitrite and ammonium chloride. The mixtures 

 of acetylene and nitrogen were dried as described by caustic 

 potash. 



Experiment 1^1. — Gas, 89 - 3 per cent of acetylene and 10*7 

 per cent of nitrogen ; pressure 3 - 2 atmospheres before and after 

 the explosion. Two estimations of acetylene in the gas after 

 the explosion gave 1*4 and 1'4 percent. In order to determine 

 the amount of hydrocyanic acid, the gases (933 cc reduced to 0° 

 and 760 mm ) from the bomb were passed slowly through a dilute 

 solution of pure potassium hydroxide. This solution was then 

 titrated with a decinormal solution of silver nitrate, requiring 

 5*2 CC to produce a permanent precipitate of silver cyanide. 

 This corresponds to 0'028 gram of hydrocyanic acid and 23 cc of 

 the compound in the gaseous state. The bomb had a capacity 

 of ly 1 ^ liters, but for convenience the result may be given as 

 the amount of hydrocyanic acid in a volume of 1 liter in the 

 bomb. It was 0*083 gram and 63-3 0C . The potash solution 

 after the titration was acidified with hydrochloric acid, boiled 2 

 cooled, then an excess of potash was added and the solution 

 was again boiled. The escaping vapor was found to be free 

 from ammonia. Nor was any found in another test similar in 

 all respects except that the titration with silver nitrate was 

 omitted. 



