Heat of Formation of Alloys. 

 Table II. 



43 



Alloy. 



Heat of Formation 

 per gramme alloy 

 in calories. 



* Heat of Formation 

 per gramme molec. 

 weight of compound 

 (see text) in caLories. 



a 

 ^3 



a . 

 o o 



Oh-*- 1 



o -a 

 o -" 



"o 



> 



Observed Volta 

 Effect in volts. 



Peltier E.M.F. 



in volts. 



Lead- Zinc Eutectic. * 

 Zinc 1*6 p. c. | 



Lead-Zinc. 1 

 Zinc 23-9 p. c. J 



-5-8 

 -3-5 



-23,800 

 -960 



•53 

 •02 



•210 



(Ayrton& Perry) 



•31 



(Pellat) 



•0008 



Lead-Bismuth. 1 

 Lead 55" 6 p. c. J 



+3-8 



+ 1,400 



•03 





•017 



Tin-Zinc Eutectic. ] 

 Zinc 8-3 p. c. ] 



+6-1 



+4,800 



•10 



•281 (A. & P.) 

 •35 (Pellat) 



•0009 



Lead -Tin. 

 Tin 90 p. c. 

 „ 61 8 „ 

 „ 21-0 „ 

 „ 5-0 „ 

 „ 2-0 „ 



+39 

 +1-9 

 -0-8 

 -11 

 -10 



+8,109 

 + 1,000 

 -450 

 ■--2,600 

 -G,500 



■18 

 •02 

 •01 

 06 

 •14 



•099 (A. & P.) 



■04 1 ^ 



scratched | ^ g 



•io I'll 



clean, j fn - 



•00001 



* The method of calculating this column may be made clearer by an 

 example. Take the case of the first alloy in the table. The atomic 

 weight of zinc being 65 - 5, a gramme-molecular weight of it, and there- 

 fore, since it is a divalent metal, of whatever combination it forms with 

 the lead, will be contained in 100+l'6x65-5 grms. of the alloy quite 

 independently of the quantity of lead "combined." Hence the heat of 



100 

 formation per gramme-molecular weight is — 5-8 X y^ x65\5 calories. 



