SCHLUNDT SPEED OF THE LIBERATION OF IODINE 



23 



Here too it is to be noticed that the entire amount of 

 iodine is liberated at the end of an hour. 



SECTION D. 



Effect of Concentration on the Speed. 



A comparison of the results in section B with those in A 

 shows that there is an increase in the speed of the iodine 

 liberation as one of the components enters in an ex- 

 cess; i. e., there is an increase in speed when one of the 

 components exists in the mixture in a more concentrated 

 form than the others. The results in section C show that 

 there is a greater increase in the speed of the reaction 

 when both the hydrochloric acid and potassium iodide enter 

 in an excess. One would also expect an increase in speed 

 as the component solutions became more concentrated, al- 

 though none of the components entered in an excess. A 

 mixture containing equivalents of the salts as fifth normal 

 solutions, and another containing them as two-fifths nor- 

 mal were investigated. The results are graphically repre- 

 sented by curves B and C, Figure 5. The curve marked A 

 represents the speed in a mixture containing the salts as 

 tenth normal solutions. 



