Investigating the rates of reaction of Sodium thiosulphate and hydrochloric acid :: GCSE Chemistry Coursework Investigation

Investigating the rates of reaction of Sodium thiosulphate and hydrochloric paneUsing my preliminary exam experiments I decided on using the followingapparatus- A conical Flask- A piece of White Paper marked with a black cross- Dilute hydrochloric corrosive- Sodium thiosulphate- Water- Measuring cylinderWe must produce a piece of coursework investigating the rates ofreaction, and the impression different changes have on them. The rate ofreaction is the rate of loss of a reactant or the rate of formation ofa product during a chemic reaction. It is measured by dividing 1 bythe m taken for the reaction to take place. There are four factorswhich affect the rate of a reaction, concord to the collision theoryof reacting particles temperature, assiduousness (of solution),surface are (of solid reactants), and catalysts. I have chosen toinvestigate the effect concentration has on a reaction.This is because concentration is the most serviceable to investigate asit would take longer to prepare a solid in powdered and unpowderedform, and it is difficult to get accurate readings out-of-pocket to theinevitabilities of human errors, and as gas is mostly colourless it isdifficult to gauge a reaction changing the pressure, and if asubstance is added to give the gas colour, it may influence theoutcome of the experiment.Also temperature is difficult to sustain and be made exact for all theexperiments.Similarly the use of a catalyst complicates things, and if used wrongly could alter the outcome of the experiment.All other factors however must be kept constant while we are varyingthe concentration.Both the sodium thiosulphate and the Hydrochloric acid are soluble inwater, so the concentration of either can be changed. However I havechosen to vary the sodium thiosulphate as it is available in largeramounts, and various concentrations are prepared.I will time how long it will take varying concentrations of SodiumThiosulphate to react with the Hydrochloric acid so that the solutionwhen placed above the white paper with the black cross is so reactedthat one cannot see the cross through the opaque liquid.In order for my findings to be valid the experiment must be a fairone. I will use the same standard each time for judging when the X hasdisappeared. I will make sure that the measuring cylinders for the HCland thiosulphate will not be mixed up. The amount of HCl will be 5 cm3each time, and the amount of thiosulphate will be fixed at 20 cm3.Also room temperature will be used as the temperature as it ispractical and will not need to be monitored.