1 45 Mixter — Heat of Formation of the 



Summary of Results. 



2 V + 50 = V0 + probably greater than 441,000° + 



V 2 6 + 3Na 2 = 3Na 2 O.V 2 6 + _ 165,800 * 



V 2 3 4- 2Na 2 2 + Na,0 = 3Na 2 O.V 2 6 + 214,800 * 



2Na a O + 20= 2Na 2 2 + 38,800 



V 2 3 + 20 + 3Na 2 = 3Na,O.V 9 0. + 253,600 



V 2 6 + 3Na 2 2 = 3Na 2 O.V 2 O s + 165,800 



V 3 O s + 20 = V.O, + 87,800 f 



V 2 4 + Na 2 2 + 2Na 2 = 3Na.O.V s O, + 174,600 * 



Na,0 + O = Na,0, + 19,400 



V 2 0, + O + 3Na a O = 3Na,O.V 2 6 + 194,000 



V 2 6 + 3Na 2 = 3Na 5 O.V 2 6 + 165,800 



V,0 4 + O = V 2 6 + 28,200 t 



V O 2 + 3Na 2 2 = 3Na,O.V.0 6 +. 340,000 * 



3Na 2 + 30 = 3Na 2 2 + 58,200 



V 2 0, + 30 + 3Na 2 O.V 2 5 + 398,200 



V 2 6 + 3Na 2 = 3Na 2 O.V 2 5 + 165,800 



V 2 2 + 30 = V 2 6 + 232,400 f 



V 2 2 + O = V 2 3 + 140,600 f 



V 2 2 + 20 = V 2 () 4 + 204,200 f 



V 2 3 + O = V 2 4 + 59,600 c t 



* Experimental result. \ Derived result. 



The heat effect of V 2 3 + O found by burning in oxygen 

 in Exp. 9 was 55 # 2°, but the method was unsatisfactory, for in 

 another experiment but little of the vanadium trioxide burned. 

 Vanadium dioxide, however, burned well and gave in Exp. 14 

 for V 2 2 + 20 = V 2 4 + 208,000°. This is a little high since 

 some pentoxide was formed, but it confirms the result by the 

 sodium dioxide method. 



The striking fact observed in the results is the high heat of 

 oxidation of vanadium dioxide, also that the results obtained 

 with impure metal indicate that each of the first two atoms of 

 oxygen combining with vanadium do not give a greater heat 

 effect than the third atom. Assuming that they give the same, 

 we have 2V + 50 = V,0 5 + 520,000 and only 441,000° were 

 found. 



After the foregoing paper was written the article on vana- 



