152 Mixter — Heat of Formation of the 



8 9 



Metal taken 6*014 7-060 grams 



„ ... f , ,(U(a)... 5-864 6-884 " 



Composit*onofmetalj ^ . 150 Q . m u 



Water equivalent of system .. . 2914 2932 " 



Temperature interval 2-502° 2*930° 



Heat effect... 7291° 8591° 



" " of iron —40 —40 



" of oxygen evolved +126 +206 



" " b... +988 +1160 



" " uranium (c) 8365 9911 



" " 1 gram of uranium- . . 1426° 1440° 



The average, 1433° times 233-5, equals 341,800° for the heat 

 of one gram atom of uranium reacting with sodium peroxide. 



Heat of Combination of ITranic Oxide with Sodium Oxide. 



Uranic oxide was made by heating cautiously uranyl nitrate 

 in platinum until the mass solidified, then heating in a glass bulb 

 to about 400° until the weight of the oxide remained constant. 

 The preparation was found to be free from nitrate and to yield 

 very nearly the theoretical amount of U 3 O s . Another prepara- 

 tion of uranic oxide was used in experiments 12 and 13. The 

 calorimetric work. was as follows : 



10 11 12 13 



Uranic oxide 5-000 5*000 5-000 10*000 grams 



Sulphur 1-000 1-000 1-000 1-000 " 



Sodium peroxide . 13. 13. 7.15 10*5 " 



Water equivalent 



of system 3012 2786 3074 3056 " 



Temperature inter- 

 val 2*305° 2*351° 2*277° 2*685° 



Heat effect 6943° 7020 c 6999° 8205° 



" " sulphur — 5270 — 5270 - 5270 — 5270 

 " " iron... —40 —40 —40 —40 



" " oxygen 

 set free 400 



Heat effect uranic 



oxide 1633 1710 1689 3295 



Heat effect for 1 

 grm. organic ox- 

 ide 327 c 342° 338° 330 c 



In mean, 334 X 286*5 = 96,100° for the heat effect of Na„0 

 + CTO,. 



