I will use 25cm3 of sodium thiosulphate, and I will then add 10cm3 of hydrochloric acid to the sodium thiosulphate, then I will record the amount of time it takes for the solution to react (until the solution is opaque), at that particular temperature, and then repeat the experiment at the other four temperatures. For this experiment I am going to use four beakers, four measuring tubes, a Bunsen burner and a thermometer. I will ensure that the experiment is safe by wearing safety goggles and not touching the hot beakers with my bare hands. I am going to repeat the experiment twice, to have a wider range of results and so that I can replace any anomalous results.
I predict that the hotter the sodium thiosulphate, the quicker the reaction, because when particles are heated, they move around more, giving each particle more chance to collide with another and react. Our reaction will not be too fast because of the concentration we have chosen. Our preliminary results showed that the higher the concentration of sodium thiosulphate, the quicker the reaction, so in theory the highest temperature at 40gm/litre, the quicker the reaction compared to the lowest temperature at 10gm/litre. The results we obtained from our preliminary experiment were backed up by the collision theory: The more collisions between particles at a given time, the faster the reaction. This theory also helps me come to my prediction of the hotter the solution the quicker the reaction.
Temp Affecting Reaction Rate
Results:
GRAPH ATTATCHED
From my results I can clearly see that the heat affects the reaction rate massively, the hotter the solution the quicker the reaction. My results show this and there is a curve in the graph, which shows this also. My results, and my prediction have also been backed up with the collision theory: The more collisions between particles at a given time, the faster the reaction.
I feel that the results I have obtained are relevant to the experiment and I had chosen the concentration of the sodium thiosulphate well, which has given me good results. We repeated the experiment twice and I have drawn this on the graph, both sets of results were close together which shows that our results were fairly accurate. I don’t feel that I have obtained any anomalous results, which pleases me because it shows that all of our results were not far off accurate.
Temp Affecting Reaction Rate
From the results obtained I have drawn a graph in which you can clearly see the speed of the reaction. You can see the reaction rate speed up from a slower rate to a faster constant one; it is at this rate that the reaction cannot be any faster. You can see this pattern in my graph, which indicates to me that the experiment was a success
I feel that our experiment was a success and we have been able to come to a sensible conclusion due to this. I feel the way we performed the experiment was good enough to get useful results and it was an overall successful experiment. The two sets of results that I obtained were never further than three seconds apart from each other, which is close enough to rely on and base a good conclusion on. The results have been backed up by information, the collision theory and the prediction, which I feel is strong enough to reach the conclusion that I have.
If I were to further my research into rate of reactions under different temperatures, I would conduct the same experiment, but maybe go into more detail such as different concentrations of sodium thiosulphate, or different amounts of hydrochloric acid, and also put the solution under a larger range of temperatures i.e. -20°c up to 100°c. Overall I feel that even this kind of experiment would produce the same pattern of results and I would still come to the same conclusion that I have.
