Mixter — Thermochemistry and the Periodic Law. 529 



are linear functions of the atomic weights of phosphorus, 

 arsenic and antimony. 



The sixth group resembles the fifth in the irregularities of 

 heat equivalents, and in both groups the only linear valuesare 

 the heats of combination of the acidic oxides with sodium 

 oxide. For the trioxides of the non-metals of the sixth group 

 they are 



Na o + SeO, Na,0 + Te0 3 



Na 2 + S0 3 

 124-0 



121-0 [124-0] 



124-0 Cal. 



Fig. 5. 



180 



j(2R+50) 



r(3Na 2 0+R 2 0j) 



R+3B 



R+30) 



As Sb 



Fig. 5. Diagram of Group V. 



The uncertainty in the value 121*0 Cal. is shown in the article 

 on the above compounds.* 



For the trioxides of the metals we have 



Na 2 + Cr0 3 Na 2 + Mo0 3 Na 2 + W0 3 Na 2 + IT0 3 



77-0 81-9 [81-6] 94-7 [90-50] 96-1 Cal. 



[82-9] [101-7] 



The calculated values are in brackets. Those in the first row 

 are derived from 96-1 - 77 = 19'1 Cal., while 829 and 1017 

 cal. are derived from 91-7 - 77 = 17'0 Cal. 

 * This Journal, xxix, 488, 1910. 



