552 Mr Robinson, The Adsorption 



Ci is the amount of acid adsorbed and a is the weight in 

 grams of the adsorbing substance, therefore — = amount adsorbed 



per gm. 



C2 is the final concentration of the solution. 



Using any two corresponding values for Ci and Cg, dividing one 

 equation by the other and taking logarithms, the following ex- 

 pression is obtained, 



log Ci - log Ci' = n [log C2 - log c/] . 



log Ci - log c/ 



Hence 



n = 



log C2 — log C.2 



Starch. 



In experiments H, B, G the starch presented a pink colour 

 after 18 hours, whereas in the others it remained colourless. 



If, in this equation for w, c/ and c^, the respective values of the 

 weight of acid used and the weight of acid left in experiment G, 

 be regarded as fixed and the corresponding values of Cj and Cg in 

 the other experiments respectively be substituted, the following 

 values iov' n are obtained: 



0-41, 0-45, 0-32, 0-35, 0'34, 030. 



Mean value 0'36. 



On substituting this mean value of n in the original equation, 

 the following values are obtained for k : 



2-74, 2-97, 



2-23, 2-35, 2-36, 

 Mean = 248. 



2-27, 2-45. 



