Rates of Reaction :: GCSE Chemistry Coursework Investigation

How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid? Temperature and Rate of Reaction Question How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid? sodium thiosulphate + hydrochloric acid sodium chloride +water + sulphur dioxide + sulphur Na2S2O3(aq) + 2HCl(aq) 2NaCl(aq) + H2O(l) + SO2(aq) + S(s) Prediction I predict that the higher the temperature, the more quickly reaction will occur. This is because with heat, the particles of sodium thiosulphate and hydrochloric acid have more energy. This causes them to move around more. It works like this for all substances, not just those two. Chemical reactions require collisions, and if particles are moving around more quickly they are obviously more likely to collide. It is just like in a crowded street. If the people are moving quickly it is more likely that they will bump into each other then if they are moving slowly. It is in this way that particles of solutions react. I found out from preliminary research that the particle theory explains that chemical reactions require a collision between the particles of the reactants, at a certain velocity and angle. If this angle or velocity is not achieved, the substances will not react together. I also found out that the factors that affect the rate of a reaction are the surface area of the solid reactant (if there is a solid reactant), the concentration of the aqueous reactant(s), the presence of catalysts and temperature. In this experiment we are only interested in temperature. Where temperature is not high enough to provide energy for the particles to move at a high enough speed, the particles will just not react, or rather, not as many particles will be able to react together in a certain amount of time. At 0-10Â °C, I predict that the reaction will take a very long time to react. The reason I say this is because although the particles will be moving around, they will not be moving at a high enough velocity. For chemical reactions to occur, the particles must be travelling at a particular speed, and this requires energy. At this temperature I do not think that it will give the particles enough energy to convert into movement. Between 11-40Â °C (this includes 3 temperature intervals - 11-20Â °C, 21-30Â °C and 31-40Â °C), I predict that the reaction will occur more quickly than that of 0-10Â °C. I think the reaction rate will decrease dramatically at this temperature. I predict this because there is more heat to provide energy to the particles of the reactants. This energy causes the particles (of sodium thiosulphate and hydrochloric acid) to