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

Investigating the arranges of reaction of atomic number 11 thiosulphate and hydrochloric acid development my preliminary experiments I decided on using the following appliance- A conical Flask- A flip-flop of White news report marked with a black cross- Dilute hydrochloric acid- Sodium thiosulphate- Water- Measuring cylinderWe must produce a piece of coursework investigating the rates ofreaction, and the effect different changes arouse on them. The rate ofreaction is the rate of loss of a reactant or the rate of validation ofa product during a chemical reaction. It is measured by dividing 1 bythe sentence taken for the reaction to take place. There argon four factorswhich affect the rate of a reaction, according to the collision schemeof reacting particles temperature, concentration (of dissolving agent),surface are (of solid reactants), and gas pedals. I have chosen toinvestigate the effect concentration has on a reaction.This is because concentration is the nearly pract ical to investigate asit would take longer to prepare a solid in powdered and unpowderedform, and it is difficult to get accurate readings collectible to theinevitabilities of human errors, and as spoil is mostly colourless it isdifficult to come close 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 usedincorrectly could alter the outcome of the experiment.All other factors but must be kept constant while we are varythe 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 bigamounts, and various concentrations are prepared.I allow time how long it will take varying concentrations of SodiumThiosulphat e 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 coordinate for my findings to be valid the experiment must be a middlingone. I will use the same standard each time for judging when the X hasdisappeared. I will make sure that the quantity 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.