Swiss chemist Hans Heinrich Landolt have discovered this reaction in 1886. The main purpose of this reaction is that when the 2 drab solutions are blended the color of the reaction turns to dull cocoa or blue reliance on the starch. Although, there are a lot of types of iodine clock reaction, in this experiment it was used from hydrogen peroxide variation.
Theory
If the process is looked through, it can be observed that all the experiments are majorly based on several reactions. Firstly, reaction between hydrogen peroxide and acidified potassium iodide is the first stage reaction which is obtained from reaction between potassium iodide and sulphuric acid. 2KJ+H2SO4→2HJ+K2SO4
H2O2+2H++2J-→2H2O+J2
At the second stage, reaction between Na2S2O3 iodine. If little amount of Na2S2O3 is used then it cut down the iodine produce to iodine ions. …show more content…
At the second experiment 10 cm3 of water was used instead of 12 cm3.Again the burettes was filled with the 0.1 M KJ, 0.5 M H_2SO_4, 0.01 M Na2 S2O3 and water and again experiment was carried out like at the first experiment.
0.1 M KJ 0.5 M H_2SO_4. 0.01 M Na2SO4 Water (H2O).
10 cm3 20 cm3 5 cm3 10 cm3
When all of these solutions were added into one tube 1 cm3 of starch. But this time 4 cm3 of H2O2 was used instead of 2 cm3 . This step was followed by starting the stop-clock and then shook for 5 second to attain homogenous solution. When the precipitation was seen, stop-clock illustrated 40 seconds. The third experiment was also the same not only first experiment but also second experiment but again there were some differences. So the third experiment was carried out with the help of changing amounts of the reagents. As the first and second experiments the same step was used for the third experiment so after filling each of three burettes with the 0.1 M KJ,0.5 M H_2SO_4,0.01 M Na2 S2O3 boiling tubes were cleaned and dried in order