Determining the Rate Equation of a Reaction Essay Example for Free

Determining the tempo Equation of a Reaction EssayThe aim of this experiment is to determine the position equation for the reply between sodium thiosulphate and hydrochloric venereal disease using the order of the reaction with watch over to each of the reagents.HCl (aq) + Na2S2O3 (aq) 2NaCl (aq) + SO2 (g) + S (s)When Hydrochloric acid is added to sodium thiosulphate, a solid ppt of sulphur is formed. I allow for use this to judge when the reaction has ended.The rate equation for this reaction isR = k HClx Na2S2O3yIn this equationR = the rate of reactionk = the rate constantx and y = order of reaction with keep to HCl and Na2S2O3 (e. g. 0, 1, 2 etc)HCl = the ingress of HClNa2S2O3 = the concentration of Na2S2O3My experiment will enable me to calculate x and y through plotting the majority against the reciprocal of the period it takes for the ppt to form.Preliminary workThe demonstration done by my teacher show that 50 cm3 of thiosulphate and 20 cm3 of deionised pissing mixed with 5cm3 of hydrochloric acid took 14.93 seconds to form the ppt. I will use this as a guide to conciliate which set of concentrations I will use to get a reasonable clip which I empennage plot.When I implement my plan, I will plot my results. Using the shape of the graph, I will indeed deduce the order of the reaction. The following graphs show the shapes I should get for each order of a reaction. I am not ever- changing the volume of hydrochloric acid because I want to test the effect of changing the concentration of the sodium thiosulphate to be able to find out the order of the reaction with respect to the sodium thiosulphate.Apparatus* White tile with X in the middle. I will house my reacting solution on this white tile and time until the cross can no longer be seen.* Stop pale to time the experiment* Stirring rod* 5 cm3 meter cylinder to measure the hydrochloric acid* ii 50 cm3 burette to measure the deionised piss and the sodium thiosulphate as it is more acc urate than a measuring cylinder.* One 250 cm3 conical flask into which I will mix my reagents* Two funnels to full my burettes, which I will remove before looking at the meniscus.* I will be supplied with deionised water, HCl and Na2S2O3Concentrations knead 1Run 2Run 3Run 4Run 5Na2S2O3 (cm3)5045403530Deionised Water (cm3)2035303540VariablesFixed independentDependentTemperature the experiment will be done at room temperature. I will simplicity the temperature because changing the temperature miscellanys the rate which will affect me results.Concentration of HCl I will keep this constant because I can only change the concentration of one reagent to see the effect this has on the rate. If I change both reagents I will not be able to tell the order of the reaction is with respect to which reagent.The white tile and cross changing this might affect my profile of the cross and the time.Total volume I will keep this the same to ensure a fair experiment and the same visibility due to sma ller volumes being more shallow and I might see the ppt at assorted times.My independent variable is the volume of the sodium thiosulphate. By altering the volume and adding deionised water, I am changing the concentration. This will enable me to observe how this will affect the rate of the reactionThe dependent variable is the time taken for the cross to disappear.Method1. fill one of the 50 cm3 burette with sodium thiosulphate and the other with deionised water using the funnel and remove funnel before looking at meniscus. The bottom of the meniscus should be on the zero line.2. measure into the conical flask the exact amount stated in the put back above of the sodium thiosulphate and the water for run 1.3. measure using the 5 cm3 cylinder 5 cm3 of HCl.4. place the conical flask on the white tile with the cross5. add the hydrochloric acid and start the stop consonant time.6. stir the mixture briefly.7. look at the conical flask from the top and stop the stop clock as soon as t he cross is no longer visible.8. write the time taken in the table.9. repeat steps 1-8 for the other runs.I will then convert the times into rates by doing 1/t. this will go along my y-axis. The volume of the sodium thiosulphate will go along the x-axis. found on the shape of my graph I will then decide what the order of the reaction is with respect to the sodium thiosulphate.SafetyChemicalHazardsHClSolutions equal to or stronger than 2 mol dm-3 but weaker than 6.5 mol dm-3 ar IRRITANT.Na2S2O3Sodium thiosulphate may be harmful if you swallow it. It may in addition irritate the eyes or lungs.Eye contact Flush the eye with plenty of water. If irritation persists, call for medical help.Skin contact Wash off with water.If swallowed If the amount swallowed is not trivial, call for medical help.SO2Major hazard Inhalation fragrance Pungent and IrritatingSContact with the eyes can cause irritation. The solid may also irritate the lungs if breathed in.Sulphur burns to give toxic gases, so should not be burned-out in the open laboratory. Wear safety glasses. Solid sulphur should pose only minor hazards unless het up(p) to a temperature at which it will burn. Safety glasses required.NaClMay cause eye irritation.Referencehttp//www.cartage.org.lb/en/themes/sciences/Chemistry/Miscellenous/Helpfile/Kinetics/Rateorder.htmChemistry 2 Cambridge Advanced Sciences Endorsed by OCR page 109http//physchem.ox.ac.uk/hmc/hsci/chemicals/sodium_thiosulphate.html