﻿46 M. C. Marignac on the Specific Heats , Densities, 

 Bisulphate of Soda : ^\o, SO 3 +n Aq. 



C 



re. c. J9. Observed. Calculated. C — 18re. 



25 0-8683 570 495 495 +45 



50 09146 1020 933 933 +33 



100 09497 1920 1823 1823 +23 



200 0-9719 3720 3615 3618 +18 



The empiric formula calculated from the first three determi- 

 nations is 



n 10 4l att , 1292 11500 



C=18w + ll-65+ a — 



n nr 



It is interesting to compare the molecular heats of solutions, 

 at the same strength, of sulphate of soda, bisulphate, and sul- 

 phuric acid. 



n. H 2 O, SO 3 . ^ a 1 O, SO 3 . Na 2 0, SO 2 . 



25 468 495 



50 914 933 926 



100 1812 1823 1816 



200 3610 3618 3602 



400 7210 .... 7194 



The molecular heat of solutions of bisulphate is always more 

 than the half of the sum of those of sulphuric acid and the neu- 

 tral sulphate. The specific heat is therefore always augmented 

 by the mixture of solutions of sulphuric acid and sulphate of 

 soda. This fact is connected with the lowering of temperature 

 produced by that mixture. 



Hydrochloric Acid : HC1 + Aq. 



n. 



c. 



P- 



r 

 Observed. 



Calculated. 



C~18». 



6-25 



0-6687 



149 



99-6 



99-6 



-12-9 



12*5 



0-7881 



261-5 



206-1 



206-1 



-18-9 



25 



0-8787 



486-5 



427-5 



426-8 



-23-2 



50 



0-9336 



936-5 



874-3 



874-3 



-25-7 



100 



0-9650 



1836-5 



1772 



1773 



-27 



200 



0-9835 



3636-5 



3576 



3572 



-28 



The molecular heat may be calculated by the formula 



C=18»- S 8-39 + l^- 2 f. 



n n z 



Hence the specific heat of solutions of chlorhydric acid is 



