SPECIFIC GRAVITY AND DISPLACEMENT OF SOME SALINE SOLUTIONS. 177 



Concen- 



KCl. 





gCl-fl 

 2 







KI. 





tration 

 in grain- 

 raolecules 

















Displace- 



Difference 

 of Dis- 



Mean Incre- 

 ment of 



Displace- 



Difference 

 of Dis- 



Mean Incre- 

 ment of 



Displace- 



Difference 

 of Dis- 



Mean Incre- 

 ment of 



per 1000 

 grams of 



ment. 



placement. 



Displacement. 



ment. 



placement. 

 dA 



Displacement. 



V 





placement. 

 d£. 



Displacement. 



V 



Water. 



A. 



dm 



m 



A. 



dm. 



m 



A. 



dm 



m 



5 









1198-104 





39-620 



1240-334 





48-067 



4 



1123-005 





30-751 



1156-880 



41-224 



39-220 



1190-788 



49-546 



47-697 



3 



1090-533 



32-472 



30-178 



1116-115 



40-765 



38-705 



1141-787 



49-001 



47-262 



2 



1059-617 



30-916 



29-808 



1076-073 



40-042 



38-036 



1093-384 



48-403 



46-692 



1 



1028-904 



30-713 



28-904 



1037186 



38-887 



37-186 



1046-189 



47195 



46-189 



1/2 



1014-001 



29-806 



28-002 



1018-343 



36-308 



36-686 



1022-778 



46-822 



45-556 



The composite salt was prepared by mixing the component salts KCl and KI in 

 the proportion of their molecular weights, 74*6 : 166"1, so that 1 gram-molecule of 

 the salt, which weighs 120 '35 grams, would contain ^ gram-molecule of each of the 

 salts, namely 37'3 grams of KCl and 83'05 grams of KI. When 1 gram-molecule 

 of this salt is dissolved in 1000 grams of water, the displacement of the resultant 

 solution may be compared with the mean of the displacements of the solutions 

 KCl + 1000 grams of water and KI -|- 1000 grams of water. 



The following table gives the results of such a comparison : — 



§ 97. Table of Values of Displacements of Solutions of Potassium Salts of the 

 Mixed Halides which have been obtained — 



A, by experiment. 



B, calculated by the method detailed above. 



B — A, the difference of calculated and observed results. 



Concentration in 



gram-molecules per 



1000 grams Water. 



m. 



A. 



B, 



B-A. 



5 



4 

 3 



2 

 1 



1/2 



1/4 



1/8 



1/16 



1/32 



1/64 



1/128 



1/256 



1/512 



1198-104 

 1156-880 

 1116-115 

 1076073 

 1037-186 

 1018-343 

 1009-071 

 1004-474 

 1002-213 

 1001-122 

 1000-535 

 1000-262 

 1000-117 

 1000-044 



1156-896 

 1116-160 

 1076-500 

 1037-546 

 1018-389 

 1009-090 

 1004-495 

 1002-228 

 1001-118 

 1000-559 

 1000-282 

 1000-133 

 1000-076 



0-016 

 0-045 

 0-427 

 0-360 

 0-046 

 0-019 

 0-021 

 0-015 

 -0-004 

 0-024 

 0-020 

 0-016 

 0-032 



This table shows that, with the possible exception of the 1/32 gram-moleeule 



solution, the mixture of wKCl-f 1000 grams of water and mKI-|- 1000 grams of water 



is accompanied by contraction. 



TRANS. ROY. SOC. EDIN., VOL. XLIX., PART I. (NO. 1). 23 



