Iodine Clock Reaction Lab Report

It was originally hypothesised that the reaction time would decrease with higher concentrations of the reactants, potassium iodate and sodium bisulfite as collision theory stated that more molecules present in a given volume meant a greater chance they would collide. Furthermore, the time was expected to decrease with higher temperatures as it influenced the reactant particles by raising their kinetic energy. However, the data collected from this experiment only partially supported this hypothesis. Although there was a general decrease in the reaction time when increasing the concentration of KIO3, 0.15M concentrations resulted in times of 45.77 and 150.47 when tested twice which was unexpectedly higher than 13.68s at a concentration of 0.1 (Table 1). Similarly, raising the concentration of NaHSO3 decreased the clock period with the exception of the 0.2M concentration as it had the lowest time of 15.39s when 0.4M was expected to be lower (Table 2) These inconsistencies for the concentration data may have been due to measurement errors during the experimental process. When increasing the temperature while keeping the concentrations constant the time decreased from 30-50°C but started to rise at temperatures greater than 60°C which may have been caused by damages to the solution due to the heat. In order to calculate the overall rate law in relation to the
In addition, the overall rate law can be explored further by using the Arrhenius equation to determine the relationship between temperature and the reaction rate as the rate constant is affected by temperature. This relationship is based upon the idea that in order to react, the reactants must possess a certain minimum amount of energy for successful collisions to occur called the activation