NEW LAW IN THERMOCHEMISTRY 



35 



Chloride. 



Bromide. 



Iodide- 



Aluminum (AljClg) ... 



Manganese 



Zinc 



Iron (Ferrous) 



Cadmium 



Cobalt 



Nickel 



Iron (Ferric) (FcjClg) 



Tin (Stannous) 



Tin (Stannic) 



Thallium (Thallous)... 



Lead 



Copper (Cupric) 



Mercury (Mercuric)... 

 Gold (Auric) 



475650 

 128000 

 I 12840 



99950 

 96250 

 94820 

 93700 



255440 

 81 140 



157170 

 38480 

 75970 

 62710 

 59860 

 28270 



410040 

 106120 

 90960 

 78070 

 75640 

 72940 

 71820 



54410 

 40830 



5090 



318780 



75700 

 60540 

 47650 

 47870 

 42520 

 41400 



10410 



Correcting these for the dissociation of the halogen molecules, 

 and for the latent heat of bromine and iodine, and adjusting all 

 to the equivalent of one halogen atom each, we have : 



Aluminum 



Manganese 



Zinc 



Iron (Ferrous) 



Cadmium 



Cobalt 



Nickel 



Iron (Ferric) 



Tin (Stannous) 



Tin (Stannic) 



Thallium (Thallous).. 



Lead 



Copper (Cupric) 



Mercury (Mercuric)... 

 Gold (Auric) 



Chloride. 



86163 



63308 

 56863 

 55013 

 54298 

 53738 

 49462 

 47458 

 46181 

 45368 

 44873 

 38243 

 36818 



15978 



Bromide. 



85434 

 70487 

 62907 

 56467 

 55247 

 53897 

 53387 



44632 

 37842 



I9124 



Iodide. 



85212 



69932 

 62352 



55902 

 56017 

 53342 

 53812 



37287 



Here again the chlorides, bromides and iodides agree quite 

 nearly in thermal value, and the differences between them are 

 doubtless due to physical causes. Other differences are ascrib- 

 able to differences in the heats of liquefaction and ionization of 

 the metals, quantities which we should expect to vary widely. 

 It is even possible that some of the metallic molecules may be 

 polyatomic, a condition for which no numerical allowance can 

 now be made. Furthermore, the solutions themselves may be 

 differently constituted, some salts being completely, and others 

 partially ionized. Hydrolysis, and perhaps polymerization also, 



