of Chemical Change. 125 



By an inspection of the above Table it will be seen that 

 from 5 to 20 grms. the rate of change is proportional to the 

 amount of free acid, above 20 grms. the rate increases more 

 rapidly than the acid. This latter fact seems strange ; for it 

 might be supposed that when large quantities of acid were 

 present the oxidation would suffer comparatively a retardation. 

 That this increase of rate in proportion to the acid takes place 

 gradually and, apparently, according to some definite law, is 



22 

 21 

















MWfM 



















20 



19 



18 



17 



16 



15 



11 



13 



12 



11 



10 



9 



8 



7 



6 



5 



4 



3 



2 



1 





















































































































































































































































































































E 















10 



20 



cX) 



So 



40 



50 



shown in the curve in the figure, the ordinate s representing 

 the rate of change and the abscissae the amount of acid. 



Table II. contains the results of a series of experiments with 

 the hydric sulphate, ranging from 3 grms. to 20 grms. Each 

 experiment consisted of *4988 grm. Fe and -1820 grm. 

 KC1 3 , 10 cubic centims. of the permanganate being equal to 

 •0192 grm. Fe ; total volume 260 cubic centims. The blanks 

 are those containing 5 grms. H 2 S0 4 , with which the other ex- 

 periments are compared. 



