OF THE ALLOYS OF COPPEE AND ZINC. 
541 
Both circumstances tend to render the accuracy of the determination less than 
usual, but this is of small moment in the final results sought, as by far the greater 
portion of the heat of dissolution of the alloys is due to the zinc. 
Table V. 
Rise in temperature 
° C. 
Water equivalent of 
Calories evolved 
Weight of copper. 
calorimeter and 
per gramme of 
contents. 
copper. 
3 • 22.54 
•44 
440 
60 
4-0741 
•545 
440-6 
59 
Mean value = 59'5. 
Heat of Dissolution of Zinc in Ammonium Cupric Chloride Solution. 
Table VI. 
Weight of zinc. 
Rise in temperature 
“ C. 
Water ecpiivalent of 
calorimeter and 
Calories evolved 
per gramme of 
contents. 
zinc. 
•5285 
•972 
438-5 
806-4 
•5001 
•9214 
438-5 
807-8 
Mean value = 807. 
Heat of Dissolution of Mixtures of Copper and Zinc in Ammonium Cupric 
Chloride Solution. 
A few experiments were made with mixtures of copper and zinc powders for the 
reason stated on p. 537. 
The agreement between observed and calculated values in Table VII. is sufliciently 
close to render it unlikely that any notable thermal effect is produced by voltaic 
action between the metallic particles and the solution. 
Table VII. 
Percentage of 
copper in 
mixture. 
Weight 
of 
mixture. 
Rise in 
temperature 
° C. 
Water 
ecpiivalent. 
Calories per 
gramme of 
mixture. 
Calories per 
gramme calcu¬ 
lated from 
Tables V. 
and VI. 
30-06 
•7366 
-984 
438-4 
584-5 
583 
43-86 
•967 
1-049 
438-8 
476 
479 
50-06 
1-0022 
-987 
438-6 
432 
433-5 
