52 



Studies on Solution. 



In the case of the methyl alcohol, a pale greenish-yellow solution 

 resulted after the salt had been allowed to remain in the alcohol for 

 several days. It is believed that this was due to traces of water, for the 

 addition of the slightest amount of water produced a similar greenish- 

 yellow solution. The ethyl and propyl alcohols remained colorless even 

 after standing above the salt for days. Three solutions of unknown 

 concentration were prepared by dropping a few crystals of the hydrate 

 NiCl2 6H 2 into methyl , ethyl , and propyl alcohols . The resulting solu- 

 tions all showed the green color characteristic of the aqueous solution. 



TABLE 20.NiCl 2 -6H,0 in Alcohols (Fig. 18}. 



The absorption curves for these three solutions show that the band 

 in the red possesses two maxima. The absorption curve of nickel 

 chloride in water, c = 0.5, is also plotted in figure 18 for the sake of 

 comparison. The absorption band for the aqueous solution has a 

 single maximum at 724/iju. In the curve for the methyl-alcohol 

 solution this maximum has been shifted to 744ju;u and there appears a 

 second small maximum at 684juju. The curve for the ethyl-alcohol 

 solution shows that the first peak has experienced a still further shift 

 towards the red to 764/i/x, and that the second peak at 684 /JL/J. has 



