The effect of temperature on the reaction between Sodium Thiosulphate (Na2S2O3) and Hydrochloric Acid (HCl) :: GCSE Chemistry Coursework Investigation

Investigating the effect of temperature on the reception between atomic number 11 Thiosulphate (Na2S2O3) and Hydrochloric Acid (HCl)Planning and PredictionApparatus ListConical Flask3 measuring cylindersSodium Thiosulphate (Na2S2O3)Hydrochloric Acid (HCl)ThermometerStop watchWhen sodium thiosulphate reacts with hydrochloric acid, the originbecomes opaque. I will investigate how the rate of this reaction isaffected when the experiment is carried out at different temperatures.The reaction that occurs produces sulphur dioxide, water and sodiumchloride. graphThe rate of chemical reactions can be affected by a number of things changes in surface area changes in concentration of the reactants changes in temperature added substances called catalysts and changes in pressure if the reactants are gases.In most chemical reactions the rate changes with condemnation, normallyslowing down.PredictionI will be investigating the effect that temperature has on thereaction between sodium thiosulphate and hydrochloric acid. I predictthat the higher the temperature, the faster the reaction will occur.This should happen because when heat is applied to a solution theparticles in the compounds move faster and therefore come into contactwith the other substance more rapidly. More importantly, thecollisions are more energetic. An increase in collisions provides more slide fastener than there is in the activation energy, so the reaction isfaster.Preliminary InvestigationIn order to discover what ratio of HCl to Na2S2O3 I needed to conducta preliminary experiment, changing the concentration of the variousreactants.I will need a time of two or three minutes at 20C, my lowesttemperature, because I predict that the reaction will speed up as thetemperature is higher, and I do not want the reaction to happen injust three or four seconds once I get to 60C as it will be difficultto measure the time accurately. GRAPHIt was di scovered after the preliminary experiments that there hadbeen some contamination so the results were inaccurate. With a largeramount of Na2S2O3 than HCl the experiment should have happened slowernot faster.After further trials I discovered thatWater 40mlsNa2S2O3 10mlsHCl 5mlsgave me an adequate starting time of approximately 300 - 330 minutesat 20C.As a result of my preliminary investigation I will add water to dilutethe Na2S2O3, as otherwise it is too concentrated and the reaction