Factors that affect the rate at which Sodium Thiosulfate (Na2S2O3) reac

I am to investigate the factors that affect the rate at which Sodium Thiosulfate (Na2S2O3) reacts with Hydrochloric Acid (HCl). When sodium thiosulfate is mixed with hydrochloric acid, a reaction takes place, leading to a precipitate of sulphur being formed. This turns the solution cloudy. I shall use this clouding to investigate a factor that affects the rate of reaction, the factor being temperature. To do this, I shall react Sodium Thiosulfate with Hydrochloric Acid at a range of temperatures, between 20 °C and 40 °C, at 5 °C intervals, leading to 5 results. The experiment shall be carried out twice, to give accuracy, and allowing me to check for agreement between results. I predict that as the temperature that the reaction takes place at increases, the less time it will take for the reaction to take place and for the solution to cloud. My prediction is based on the collision theory, which says that  · Reacting species must hit together  · Species must hit together with more than the activation energy needed Increasing the temperature of the atoms taking part makes them move more and faster, enabling more collisions to take place, speeding up the reaction. The added heat energy also allows more collisions to have the required activation energy, again, speeding up the reaction. In order to make this experiment a fair test, I changed only one input variable, the temperature. I kept the amount and concentration of the liquids the same (20m...