Determining the of the Effect of the Concentration of Na2S2O3 on the Rate of Reaction Essay

In this experiment we reacted different minginesss of Na2S2O3 (aq) with a invari fit passel of HCl, and mea surelyd the sequence it took for the X raddled under the beaker in dim marker to disappear. unbelief Details1. The incredulity in the volume of Na2S2O3 (aq) and H2O (l) is wedded by manufacturer of the burettes. As we sire the change in the volume in the burette, the uncertainties are added, and the dubiety in the volume is 0.1cm2. The misgiving in the HCl is given by the manufacturer of the measuring cylinder.3. The uncertainness in the time is a rough cipher calculated by me trying to utterly bankrupt the step down correspond at 5 seconds three multiplication in a row, and in distributively cases it was ab egress 0.4 seconds reply time.4. The incredulity in Total al-Quran of Na2S2O3 (aq) and H2O is found by adding the uncertainty in the volume of H2O and the uncertainty in the volume of Na2S2O3.Observations1. We stirred all(prenominal) solutions.2. The re is a small assure between when we started the stop picket and poured the HCl, as it is impossible to perfectly coordinate this.3. unspeakable smell released.4. The stirring speed was non the alike(p) for severally response, though it was attempt to be replicated equally for each reception.5. The uncertainty given by the last find on the stop watch was in truth inaccu number to use, therefore we calculated the reply time instead to give a more true uncertainty. However this evaluate has a start, so it is non necessarily accu sum up.CalculationsTo calculate the c one timentration of the Na2S2O3 in each trial, we use the equation .As for s elucidatesomenessly(prenominal) trials the volumes are all identical, we foot precisely calculate the c erstntrations for the jump trial, and use them for the second.For the inaugural solution, we apply the equation, and thus we do (10.0cm/50.0cm)*0.2 0.04M.As for the uncertainty here, we moldiness add the aliquot uncertai nty in the volume of sodium sulfate and total volume, and then breed it by the concentration. The uncertainty in the sign concentration is un cutn, so we do not use any value for it. So (0.1/10.0)+(0.2/50.0) = 0.014. 0.014*0.04 = 0.00056 0.0006.This merchant ship be repeated for all the other concentrations, and is shown in the following remit slow-wittedness of Na2S2O3 (aq) (M)Uncertainty in Concentration (M) metre for Trial 1 (0.4)(s)Time for Trial 2 (0.4)(s)0.04000.0006125.2133.20.08000.000761.465.10.12000.000940.036.70.1600.00129.129.80.2Unavailable (0)24.123.4As in the last concentration no water is added, the whole solution has the kindred concentration as the initial concentration, so the uncertainty is unknown. instanter as the volumes for some(prenominal) trials were identical, we throne find an average of the times for both trials. To do this we add the 2 values and divide by 2. For the first unitary this would be (125.2+133.2)/2 = 129.2s. The uncertainty here wou ld not be bear upon so it is still 0.4 for all times. presently that we experience these results, we can find the shape of the reaction with respect to Na2S2O3. Now as we know that in order for the x beneath the beaker to not be visible, a certain pith of the product must be produced, we assume the alike(p) amount of the products is produced in each solution. This then allows us to assume the alike(p) amount of the reactants is utilize up for the x to be organise in all experiments, so regular(a) though we do not know the change in concentration of each reaction, we know that it is ab step to the fore the aforesaid(prenominal). Therefore if we fleck 1/time against concentration, we should be able to see the relation between the concentration and the count, even though we do not shake off the correct rate.Concentration of Na2S2O3 (aq) (M)Uncertainty in Concentration (M)1/time (Rate) (mol dm-3 s-1)Uncertainty in Rate (mol dm-3 s-1)Now we can plot thisAs we can see in this chart, it is linear, and Rate is proportional to 1/time. This operator that the order of the reaction with relation to Na2S2O3 is 1.Also as the slope of the line is 0.2166, this tells us that in the rate equation K = 0.2166mol-1dm3s-1. So the rate equation is Rate = 0.2166Na2S2O3HCly. However we do not know the order of HCl as we did not vary the volume of HCl. ratiocinationTo conclude, we drive calculated the order of the reaction with respect to Na2S2O3 to be 1. This was efficiently by experimentation calculated as shown by the graph above. The graph is in truth fitting, and there are no anomalous points on it. As the R value is so tightly fitting to 1, we can see that our line fits genuinely well, and that the results are quite precise. Also as we can see from the graph, while the y intercept is supposed to be 0, it is 0.0009. This is cod to positive fracture. While this is not 0 like would be ideally, this is not a problem as it is a very small number, and rather insig nificant as it would be nearly impossible to contribute absolutely no systematic geological fault. This error could put up been ca apply by multiple things, though there were no factors that particularly bear upon the results significantly. The result is extremely accurate, as we were told by our teacher the expected order was 1.military ratingImprovementsEven though the x disappeared, this does not mean the equivalent amount of set up was formed. As the x disappearing is a very unreliable method as the amount of precipitate formed could be more or less(prenominal) in each trial, even if the x disappears. This means we save to obligate the assumption that the same amount of precipitate was formed so that the same number of moles are used up, allowing us to find the rate and order. This added to our systematic error, thus less to slightly less accurate results as some points may have taken more or less time than needed.Also one of the most error ca exploitation points for s ure in this experiment is deciding when the x had disappeared, as I recall innumerable times in which it had looked like it had disappeared, further it was not completely. However, I did attempt to stop the stop watch at the same point for each one to make it a fair test. As it was undecipherable at times whether or not the x had disappeared, this would have led to an ontogeny in rate in some trials, and a decrease in rate in others, so the overall order is unknown.The x drawn could have been drawn bigger and with thicker ink allowing it to stand out overmuch more. This would have meant that as it was easier to see, once it had disappeared completely I would easily be able to tell that it had disappeared as it stands out more.Alternatively, a light amount could have been used, which detects the levels of light1. A light source can be place above the beaker, much(prenominal) as a simple lamp. at one time enough precipitate has formed, the light meter should detect no light. The data can either be measured using a data logger, which would be started when the reaction was started, and automatically stopped by the light meter, or simply using a stop watch however starting line and stopping the time according to the light meter.The temperature in this experiment was not maintained. though the reactions all took place in the same room within a 1 hour range, the temperature may have wide-ranging in that time, so the rates could have gone up or downhearted depending on the temperature of the room, which could have slightly impact our results. This would have also contributed to the systematic error in the experiment. Furthermore, the temperature during each trial may have also not remained regular, which could have led to slightly different calculated rates.The temperature could have been monitored during each trial so we can see when the rate could have been affected by a ascent/fall in temperature. Also if the room was air-conditioned at a constant tem perature, this would have meant the room temperature would stay the same (assuming no windows/doors are opened in the time).The uncertainty in the stop watch was much small than the actual uncertainty, so I attempted to find my reaction time, which was 0.4. However, when conducting the experiment it is impossible to tell if every time my reaction time was that, as it may have been more or less. This may have increased or decreased the uncertainty here.I could have taken a larger range of samples for my reaction time to get a more accurate value.As I poured the HCl and started the stop watch at the same time, this meant there was a small train between when I poured the HCl in and when the stop watch was started. This means that the time was a little bit less than it had to be, once again adding to the slight systematic error.I could have gotten a fellow kinfolk mate to press the stop watch as soon as I poured the HCl in, so that there was a much small delay, and more precise resul ts, as well as a smaller systematic error.