246 



TABLES 270-272. 



HEATS OF FORMATION OF IONS IN KILOGRAM-CALORIES. 



+ and signs indicate signs of ions and the number of these signs the valency. For the ioni- 

 tation of each gram-molecule of an element divide the numbers in the table by the valency, e. g., 

 9-3 8 r - Al =9.03 gr. A1+ 4-40.3 Kg. cal. When a solution is of such dilution that further dilu- 

 tion does not increase its conductivity, then the heats of formation of substances in such solutions 

 may be found as follows : FeCljAq + 22.2 + 2 X 39.1 = 100.4 Kg. cal. CuSO 4 Aq = 15.8 

 -t- 214.0 = 198.2 Kg. cal. 



TABLE 271. Heats of Neutralization in Kilogram-Calories, 



The heat generated by the neutralization of an acid by a base is equal, for each gram-molecule 

 of water formed, to 13.7 Kg. cal. plus the heat produced by the amount of un-ionized salt formed, 

 plus the sum of the heats produced in the completion of the ionizations of the acid and the base. 

 (See also p. 209). 



TABLE 272. Heat of Dilution, H 2 S0 4 . 



In Kilogram-calories by the dilution of one gram-molecule of sulphuric acid by m eram-mole- 

 cules of water. 



SMITHSONIAN TABLES. 



