Predictions
I predict that the hotter the temperature of the thiosulphate the faster the reaction and the quicker the reaction time. I have made this prediction based on the fact that I have done this experiment before and on results of this previous experiment.
How I will keep the experiment accurate
Once I have timed the experiment I will make the time to two decimal places. I will repeat the experiment three times and compare results and make average results. I will also repeat measurements. This should help keep the experiment as accurate as possible.
Results tables
20th November
27th November
27th November
Average Results
There were a few anomalous results but when this occurred did the experiment again.
We also used average results to make sure the results were accurate and to compare. In two line graphs as you can see.
Variables
The key variables I used in this experiment are the temperature and time. This is because I will be changing the temperature of the Sodium Thiosulphate to record the time of the reaction. There fore the time will change every time the temperature does.
The temperature is the most important variable because the experiment is based on this. Time is also important because you can change how long you leave the Thiosulphate on the Bunsen burner but this also depends on the temperature you want. We also test the reaction time so time is important in this experiment.
WHAT DOES THE EXPERIMENT SHOW
The experiment shows that the hotter the temperature of the Sodium Thiosulphate the faster the reaction time of the Hydrochloric acid and Thiosulphate. Previous practical work helped me understand the results of this experiment because I have done the same experiment before. This also helped my prediction that agreed with the results. I based my prediction on results of past experiments.
Why I think the experiment worked well
And why I think my observations were accurate
I think the experiment worked well because it followed my predictions, which were based on past experiments, and the experiment was as accurate as possible.
I think my observations were accurate because I kept the results to two decimal places. I also did the experiment three times and if I got any anomalous results I did the measurements and temperature again. This why I think my observations were accurate.
How I could improve this experiment
When we did the experiment we ran out of Sodium Thiosulphate so we had to change the bottle. This bottle could have been a different concentration and could therefore be the cause of strange results or inaccurate results. I could improve this by using a bottle of Sodium Thiosulphate that is full. This would mean that it would be unlikely that I would run out of it. I tried my hardest to keep measurements as accurate as possible but I could improve this by trying even harder.
Why I think I have enough results to draw a conclusion
I haven’t actually got five results on a graph I have four because I didn’t get the time to do a fifth result in the first lesson we did this practical work. However I still think I have enough results to draw a conclusion based on past results and practical work on the same experiment. After doing this experiment numerous times I have come to a conclusion based on past experiments and on experiment I have just done. The conclusion is that in all the experiments I have done the same thing has occurred. The hotter the Sodium Thiosulphate the faster the reaction time.
Other experiments that could be carried out to extend this work
Other work I could do is to change the concentration of the Hydrochloric acid and add Thiosulphate and test reaction time. We could change the concentration of the Hydrochloric acid and the temperature of the Thiosulphate, or vice versa, change the temperature of the Hydrochloric acid and change the concentration of the Thiosulphate.
However this might not be as safe as the first or second experiments that I said could be extended work.
