1901—2.] Action of Silver Salts on Ammonium Persulphate. 91 
Kegarding the action as determined by the equation 
(c) S 2 0 8 " + 2Ag’ + 2H 2 0 =5*: 2 SO/ + 4H’ + Ag 2 0 2 
the expression for the reaction velocity is 
- 1 
where C denotes the concentration of persulphate ions, the con- 
centration of the silver ions being taken as constant. As the 
solutions to begin with were only semi-normal as regards ammonium 
persulphate, the concentration of the persulphate ions may be 
assumed, with a fair degree of accuracy, to be that of the unde- 
composed persulphate. 
Integration of the above equation gives 
or, changing to common logarithms (which gives a new constant K), 
L C 0 T r 
t log '°cr R; 
where C is the initial persulphate concentration, and G t is the con- 
centration after a time t. 
If x is the increase of acid concentration in the time t, and a is 
the increase in infinite time, then 
C 0 _ a 
C t a - x ' 
Hence ilog — a =K. 
t *a-x 
Values of K for the different solutions. 
Time in 
Days. 
Sol. I. 
Sol. II. 
Sol. III. 
Sol. IV. 
Sol. V. 
Sol. VI. 
1 
•082 
•064 
•068 
•067 
•090 
*086 
2 
•083 
•065 
•066 
•068 
•089 
•071 (?) 
3 
*081 
•065 
•067 
•068 
•098 
*088 
4 
•084 
•065 
•069 
•069 
•093 
•088 
5 
•085 
•066 
•069 
•069 
•C94 
•087 
6 
*084 
•067 
•068 
•070 
•094 
•087 
7 
*085 
•067 
•068 
•071 
•094 
•089 
8 
•085 
•068 
•070 
•071 
*095 
•091 
9 
•084 
•067 
•069 
•071 
•095 
•090 
10 
•085 
•068 
•070 
•071 
•094 
•090 
