SPECTROPHOTOGRAPHY OF CHEMICAL REACTIONS. 



59 



increase the stability of the solution. Solutions of uranous salts sometimes 

 form precipitates on standing. Uranous chloride was dissolved in the follow- 

 ing solvents, and mixed with the following compounds: 



Parts 

 uranous 

 chloride 

 solution. 



1.0 

 1.0 

 1.0 

 1.0 



Parts of solvei't added. 



1.0 

 1.0 

 1.0 

 1.0 

 1.0 

 1.0 

 3.0 



10 



10 



10 



10 



10.0 



10.0 



10.0 



10 



10 



10 



10 



Parts of hydrogen peroxide 

 necessary for oxidization. 



water 



ethyl alcohol 



glycerol 



hot water 



water +H 2 S0 4 



acetic acid 



acetone 



nitric acid 



calcium nitrate in 2H 2 + 3CH 4 . 



hydrochloric acid 2.0 



aluminium chloride in water 0.25 



10.0 sodium perchloride in water 0.2 



10 . aluminium chloride in hot water .... 0.16 



7 . hot hydrochloric acid 0.8 



S.O hot nitric acid 0.0 NO 



0.2 



0.2 



0.35 



0.2 precipitated. 



0.1 



.0 

 .0 



0.2 



0.2 precipitated. 



2.0 



0.2 



formed. 



A spectrogram was made showing the effect of the addition of hydrogen 

 peroxide to a solution of about 0.75 normal concentration of an aqueous solu- 

 tion of uranous chloride. The uranous chloride solution did not show any 

 uranyl bands at all, and even when the uranous bands appeared very strongly 

 there was very little absorption in the region from X 3500 to X 4200. The edges 

 of the uranous bands were well denned, there being four very strong bands 

 extending between the following limits : X 4250 to X 4400, X 4700 to about 

 X 5080, X 5400 to X 5600, and X 6100 to X 6800. The transmission between 

 these bands was quite strong and appeared to be uniformly distributed. 



The addition of hydrogen peroxide caused the uranous bands to decrease 

 in intensity. As far as the quite sharp uranous bands are concerned it seems 

 that the individuality of these bands decrease at about the same rate; but 

 the X4340 band is replaced by the blue-violet uranyl band, and the X 5500 

 band is also apparently replaced by wide general absorption in this region, 

 extending 500 or 600 Angstrom units. On the other hand, the transmission 

 seems to be pretty complete in the red and, with the exception of the very 

 weak uranyl bands, in the region X 4500. 



A, plate 44, represents the effect of the addition of hydrogen peroxide to 

 a solution of uranous chloride in water, acetone, and hydrochloric acid. The 

 solution did not contain the right proportion of the solvents to show the tine 

 structure of the uranous and uranyl bands brought out by some acid acetone 

 solutions. The spectrogram shows very clearly the various uranous bands, 

 and how they are replaced by the uranyl bands as hydrogen peroxide is added. 



The band that appears at about X 4970, and is quite strong on several 

 of the strips, is a uranous band, and disappears when sufficient hydrogen 

 peroxide is added. In the upper strip, which represents the absorption of the 

 uranyl salt, there is a wide, very diffuse and weak region of absorption, running 

 from about X 5000 to X 5100. 



