LIQUIDS AND ALUED EXPERIMENTS. 



75 



But the following data for dilute solutions of CaCL in the same vessel will 

 exhibit much more striking anomalies in this respect. 



50. The Same, Continued. — The preceding solution, being diluted with 

 about an equal bulk of water, showed a density of 1.105 at 23°. This is 

 equivalent to 12.2 grams in 100 grams of solution, or 13.9 grams in 100 

 grams of water. The vapor pressures are correspondingly increased to 

 7r' = 7r(i —0.075), for which tables vrere com.puted. The diffusion results 

 are given in table 31 and fig. 28 A, the apparatus and equipment being 

 otherwise the same. The mean rate of diffusion corresponds to the fol- 

 lowing data, again adducing a small increase of k as compared v»'ith the 

 former solution. 



V(j = o.oo72 c.c./day and io"'k = o.352 

 The curve shows no initial disturbances. 



51. The Same, Continued. — The solution was then further diluted to 

 about one-half, /. e., to about one-quarter of its original strength. The 

 density found was 1.058 at 1 8° C, which is equivalent to about 7.1 gramxS 

 CaClo in 100 grams of solution or about 7.6 grams CaClo in 100 grams of 

 water. The vapor pressures were therefore taken as 7r' = 7r(i —0.042). 



The record of results is given in table 32 and fig. 28 b. 



The mean rate of diffusion would correspond to 



10 = 0.0067 c.c. day or 10^ = 0.254 



which is actually smaller than the constant for the half strength of solution. 

 The fitial rate, however, is 



?o = 0.0097 c.c. day or 10^°^ = 0.368 

 a slight increase on the preceding rate. It is probable, therefore, that the 

 first rate w^as obtained in the absence of equilibrium conditions. The curve 

 shows marked initial disturbances, there being no effective diffusion within 

 the first ten days. 



