50 



ENERGY CHANGES INVOLVED IN DILUTION OF AMALGAMS. 



known error of the scale, and for the exposed thread. Ample time was 

 allowed for the cell to reach the temperature of the bath. The measurements 

 follow : 



Temperature Coefficient of Cadmium Amalgam Cells. 



The multiple cell after measurement at zero was returned to the warm 

 thermostat, and fifteen minutes later it gave almost exactly its original read- 

 ings (see series II). The results at o for combinations 1-3 and 1-4 

 are not given in the table, because at that temperature they showed an ab- 

 normally low potential, evidently due to a partial freezing of amalgam I ; 

 this is consistent with the observations of Korp and Bottger. 05 This fact 

 does not, of course, interfere with their use at a higher temperature. 



It becomes now a matter of great interest to compare this change of poten- 

 tial with the requirements of the gas law, by comparing the temperature 

 coefficient with the temperature-pressure coefficient of a perfect gas over 

 the same range of temperature. 



The following table gives the temperature coefficients referred to the 

 observed potentials at zero : 



2-4, from 30.00 to 15.20 . 



Atz O.OOI659 



2-4, from I5.20 c 



to 0.00 



Ait 



14.80 X 0.030826 



n Q dt 



1-4, from 30 to 15.20' 



Jtt 



_ 0.001719 

 15.20 X 0.030826 



0.002578 X 288.20 



= 0.00364 



= 0.00367 



VK 



14.80 X 273.08 X 0.050332 

 1-3, from 30 to 15.20 . 



Jtt 0.00177 X 288.20 



" 14.80 X 273.08 X 0.034130 



Average 



V 



= 0.003655 



= 0.00366 



0.00366 + 



M Zeit. Anorg. Chem., 25, 59 (1900). 



