The reaction between Sodium Thiosulphate and Hydrochloric acid :: GCSE Chemistry Coursework Investigation

Investigate what happens to the rate of reaction when the concentration of Sodium Thiosulphate is altered in the reaction between Sodium Thiosulphate and Hydrochloric acid. Rates of reaction investigation Aim The aim of this coursework is to investigate what happens to the rate of reaction when the concentration of Sodium Thiosulphate is altered in the reaction between Sodium Thiosulphate and Hydrochloric acid. Below is the reaction equation Sodium + Hydrochloric Sodium + Water + Sulphur+ Sulphur Thiosulphate acid Chloride Dioxide Na2S2o3 (aq) + 2Hcl (aq) 2Nacl (aq) + H2o(l) + So2(g) S(s) Prediction I predict that as the concentration of Sodium Thiosulphate decreases, the reaction time will increase. The reason I believe this is because the collision theory says, that when there is a high concentration of Sodium Thiosulphate, there are more particles of Sodium Thiosulphate floating around the water molecules, this increases the chance of collisions between the important particles so therefore it will take less time for the reaction to occur. Similarly, when there is a lesser concentration of Sodium Thiosulphate and a higher concentration of water, there are less particles of Sodium Thiosulphate floating around the water molecules, this decreases the chance of collisions between the important particles so therefore it will take more time for the reaction to occur. Method Equipment needed * 1 Bottle of Sodium Thiosulphate * 1 Bottle of Hydrochloric Acid * Water * 1 Beaker * 2 pipettes * 2 measuring cylinders * Goggles * Paper with "X" mark * Stop clock In order for me to carry out my experiments I would need to change the concentration of Sodium Thiosulphate in the reaction between Sodium Thiosulphate and Hydrochloric Acid. I would do this by keeping the total volume of the reactant 50 ³ all the time. I would change the concentration of Sodium Thiosulphate by decreasing the volume of Sodium Thiosulphate and increasing the volume of water in ten different experiments. In each of the experiments I would keep the amount of Hydrochloric acid the same and this would be 5cm ³. Below is a table of how I would do this. GRAPH In order for me to get an accurate result, I am going to carry out these experiments three times. I will then work out the average result for all three and use that to create my graph which will tell me how the rate of reaction is affected by using different concentrations. In order for me to carry out my experiments I would need to follow the following procedures: 1. Draw out an "X" on a paper and place it underneath the empty