98 



A STUDY OF THE ABSORPTION SPECTRA. 



hydrochloric acid caused the uranyl bands to break up into several com- 

 ponents. It also caused a very great amount of increased absorption 

 throughout the spectrum. Strip 1 showed absorption of the shorter wave- 

 lengths to X 3800, strip 3 to X 4700, strip 4 to A 3700, strip 5 to X 4200 (and 

 a broad diffuse band at X 5100), strip 6 to X 6000, and strip 7 to A 6300, 

 approximately. For the solution containing hydrochloric acid the uranyl 

 bands are not as strong as for the pure acetone solution. The wave-lengths 

 of the uranyl bands are as follows (in acetone) : 



In the pure acetone solution the a, b, and c bands each contain two 

 bands of about equal intensity, that almost blend into a single band. There 

 are fine bands at XX 4980, 5000, 5030, 5240, 5270, and 5295. 



Uranyl Chloride in Acetone and Water. 



A spectrogram was made showing the way the uranyl bands of an 

 acetone solution are affected by hydrochloric acid and water. Strip 1 is 

 the absorption of a 2 mm. solution of 0.0088 normal uranyl chloride in 

 acetone; strip 2 is the same to which hydrochloric acid has been added so 

 as to make a depth of cell of 3.2 mm.; strip 3, where water has been added 

 to make a depth of cell of 3.4 mm.; strip 4 to 4 mm.; strip 5 to 5 mm.; and 

 strip 6 to 11 mm. In the latter case a white precipitate was formed. 



The addition of hydrochloric acid causes the uranyl bands to break 

 into various components. The addition of water causes these components 

 to broaden, weaken, and finally to form very faint, diffuse bands. As long 

 as the components appear their wave-lengths remain unchanged as water 

 is added. 



Uranyl, Chloride, Temperature Effect. 



A spectrogram (Plate 61, A) was made of the absorption spectrum 

 of a normal aqueous solution of uranyl chloride, the depth of cell being 

 3 mm. Exposures were made to the Nernst glower for 90 seconds (current 

 0.8 ampere and slit-width 0.20 mm.). The time of exposure to the spark 

 was 6 minutes. Starting from the comparison spectrum, the temperatures 

 were 6, 18, 34, 52, 68, and 82. 



At 8 the ultra-violet band extended to X 3550, the blue-violet band 

 from X 4000 to X 4450. The bands a, b, and c appeared, but the a band is 

 very faint. The wave-lengths of the b and c bands were XX 4565 and 4725. 



