MAPPING ABSORPTION SPECTRA OF VARIOUS SALTS. 43 



THE ABSORPTION SPECTRUM OF SOLUTIONS OF CERTAIN SALTS 



OF URANIUM. 



For a full discussion of the absorption spectrum of a large number of 

 uranium solutions the reader should consult Publication No. 130 of the Car- 

 negie Institution of Washington. In the following pages only a few solutions 

 are discussed, these being for the most part solutions of the uranyl salts in some 

 of the organic solvents. This was taken up because corresponding neodymium 

 solutions were being investigated, and it was thought to be of some interest 

 to study a few uranyl solutions in the same way. In the description of the 

 bands of uranium solutions it must be remembered that the terms wide, fine, 

 sharp, narrow, broad, etc., are relative to other uranyl or uranous bands 

 and not to neodymium or samarium bands. A sharp uranyl band would, 

 therefore, be a very wide and hazy neodymium band. 



Uranyl Chloride in Propyl Alcohol. 



The absorption spectrum of uranyl chloride in propyl alcohol is given in 

 B, plate 18. The absorption bands of the propyl alcohol solution are quite 

 strong and appear at the following positions: XX 3980, 4100, 4230, about 4400 

 (this band is apparently double), 4580, 4750, and 4910. The upper strip shows 

 quite well the difference in intensity of the a and b bands. In this strip the 

 b band is very broad and strong, running from X 4690 to about X 4820. On 

 the other hand, the a band is quite weak, and is not more than about 40 

 Angstrom units in width. 



Uranyl Chloride in Isopropyl Alcohol. 



A, plate 14, gives the absorption spectrum of uranyl chloride in isopropyl 

 alcohol. The blue-violet band is seen to be quite prominent, its middle coming 

 at about X 4350, about 100 Angstrom units farther towards the red than for 

 the aqueous solutions. The uranyl bands are very weak and diffuse, being 

 much more so than for the propyl alcohol solution. The a band does not 

 appear on the spectrogram. The following bands show: X 4100, X 4250, X 4360 

 (these two bands practically merge into one another), X 4560, and X 4750. 



Uranyl Chloride in Butyl Alcohol. 



The absorption spectrum of uranyl chloride in butyl alcohol is given in 

 the three upper strips of A, plate 15. It will be seen that the uranyl bands are 

 very wide and diffuse. The following bands can be distinguished from the gen- 

 eral absorption: XX 3850, 3960, 4100, 4240, 4390, 4560, 4750, 4970. The bands 

 are all very diffuse, the last band being about 150 Angstrom units in width. 



Uranyl Chloride in Isobtttyl Alcohol. 



The absorption spectrum of uranyl chloride in isobutyl alcohol is given 



in B, plate 19. The spectrogram gives the following uranyl bands: XX 4400, 



4560, 4720, and 4900. 



Uranyl Chloride in Ether. 



The following uranyl bands have been photographed for a solution of 

 uranyl chloride in ether: XX 4040, 4160, 4300, 4444, and 4630. The solubility 

 of uranyl chloride in dry ether is very small. 



