The effect of temperature on the rate of reaction - page 8
Keywords: rate of reaction, temperature, chemistry
By abdul on 20/11/2006 17:43:08
Level: GCSE Key Stage 4 (Years 10-11)
Page Number: 8 of 8 pages: 1 2 3 4 5 6 7 8
possible reason could be that sodium thiosulphate has lost some heat while pouring it in the conical flask and mixing it with HCl.
According to my evidences my conclusion, which is that as the temperature increases the rate of reaction increases and as the temperature increases the time taken for the cross to disappear decreases to the more frequent collisions per second, is right and that is because I have repeated the experiment five times; also I have repeated the anomalies which do not fit in pattern with the rest of results in order to get the reliable and precise results.
Also
As I said above the reaction between sodium thiosulphate and the HCl is exothermic as the mixture’s temperature rise up and so the inaccuracy between the mixtures temperatures when repeating or when doing it for other temperature range is possible and unfortunately I do not think we can do anything towards this problem.
I still think that I could get even more precise results if I used the light transmitter instead of relying on the human eye detecting when the cross will disappear, as the light transmitter can measure the amount of light that coming through the mixture by a bulb or a light source placed on the other side of the conical flask. The light transmitter can tell when there is no light coming through the mixture which means that the solution has become too precipitate and this will give the exact amount of time taken for the precipitate to obscure the sight. Below there is a table of results taken by the software “Science Investigations 2” which compare the results taken by using the cross, and the results that I would take if I used the light transmitter.
Temperature (°C) Time taken by cross method(s) Time taken by using light transmitter (s)
0 326 485
30 36 60
50 17 23
70 6 9
100 3 3
Also I wished to extend it more and to see how changing the concentration of the hydrochloric acid can change the rate of reaction between sodium thiosulphate and hydrochloric acid, and I wanted to compare how the temperature of different HCl concentrations can affects the rate of reaction, but unfortunately I did not have enough time.
Done By Abdul
Bibliography
• GCSE Science Class Book – By David Baylis, Graham Booth and Bob McDuell
• AQA GCSE Chemistry second edition – by Terry Mansfield, Ian Brandon and Rafael Fernandez.
• OCR Double Award Science Staged Assessment Year 10, GCP.
• Focus Educational Software, Science investigations2.
• http://www.sci-journal.org
Last 5 comments…
IT really good
YIM (6-Mar-2011)