LIQUIDS AND ALUED EXPERIMENTS. 



75 



But the following data for dilute solutions of CaCl 2 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 were computed. The diffusion results 

 are given in table 31 and fig. 2S 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 with the 

 former solution. 



''0 = 0.0072 c.c./day and io 10 k = o.352 

 The curve shows no initial disturbances. 



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

 about one-half, i. 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 grams 

 CaCl 2 in 100 grams of solution or about 7.6 grams CaCl 2 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. 



Table 32.— 



-Air-air through CaClo 



solution (7.6 grams in 100 



jrams 



water). 



Vessel 





C (singl 



e tube) 



. Constants a? 



» in table 



30. p w =\. 



058 at 18 . 



Date. 



Barom- 

 eter. 



t 



II 



v 



Date. 



Barom- 

 eter. 



/ 



H 



v 



Nov. 18. 



76.26 





 18.0 



68.88 



6.673 



Dec. 6 



• 75-75 





 17-3 



67.74 



6-577 



19. . 



: 76.29 



17.8 



68.78 



6.668 



7 



• 76.14 



■7 



8 



67-77 



6.570 



20. . 



1 75-97 



17.6 



68.65 



6.658 



9 



. 76.28 



'7 



8 



67.81 



6.574 



21 . . 



76.31 



"7-3 



68.69 



6.669 



10 



• 76.33 



17 



8 



67.76 



6.569 



22. . 



75-94 



•7-3 



68.70 



6.670 



1 1 



• 75-92 



'7 



5 



67.64 



6.563 



23. . 



76.08 



•7-5 



68.66 



6.662 



12 



76.16 



17 



6 



67-54 



6.551 



25. . 



74-9' 



17-5 



68. 6c, 



6.664 



'3 



• 77-io 



'7 



3 



67.31 



6-535 



26.. 



76.20 



17-3 



68.59 



6.659 



•4 



• 76.74 



17 







67.24 



6-534 



27. . 



1 76.38 



17. 1 



68.58 



6.662 



16 



• 75-40 



17 







67. 10 



6. 520 



29. • 



I 76.95 



16.7 



68.48 



6.660 



17 



• 76.45 



'7 



2 



66.96 



6.502 



30.. 



! 76.79 



16.6 



68.13 



6.628 



18 



. 76.40 



17 



3 



66.67 



6.473 



Dec. 2. . 



1 76 . 60 



16.7 



67.66 



6.580 



'9 



• 74-34 



17 



5 



66.79 



6.480 



3- ■ 



76.45 



.6.5 



67.63 



6.582 



20 



. 75-88 



17 



6 



66.65 



6.464 



4. . 



76.30 



16.7 



67.65 



6-579 



21 



• 76.57 



17 



7 



66.65 



6.462 



5- • 



! 77-o6 



17.0 



67.59 



6.568 



23 



• 76.75 



17 



4 



66.27 



6.432 



The mean rate of diffusion would correspond to 



v Q = 0.0067 c.c., day or io 10 /< = 0.254 

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

 The final rate, however, is 



v = 0.0097 c.c. day or io 10 *: = 0.368 

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

 first rate was obtained in the absence of equilibrium conditions. The curve 

 shows marked initial disturbances, there being no effective diffusion within 

 the first ten days. 



