556 



Mr Robinson, The Adsorption 



25 c.c. of the clear liquid were withdrawn, shaken about with much 

 water and the whole was titrated against baryta of known strength, 

 phenolphthalein being used as indicator. 



In each experiment, the cellulose became darker in colour, the 

 stronger solutions of the acid producing the deepest colour. 



Strength of solution, 1 c.c. contains •01161 gm. of HBr. 



Cellulose and Hydrogen Bromide. 



The exponential formula was again employed and the following 

 values were obtained for n : 



0-37, 0-37, 0-30, 030. 

 Mean = 0-33. 

 The corresponding values for k are 



1-98, 2-04, 2-08, 1-88, 1-89. 

 Mean = 1-97. 



If the corresponding values of log - and log k + n log Cg be 

 plotted against each other, the following results are obtained. 

 — is the weight of acid adsorbed per gram of cellulose, Cj is 



Cb 



the final concentration of the solution. 



