The effect concentration of hydrochloric acid has on the rate of reaction -- A* - page 4
Keywords: Rate of reaction hydrochloric acid sodium thiosulphate concentration
By georgie1 on 31/12/2009
Level: GCSE Key Stage 4 (Years 10-11)
Page Number: 4 of 8 pages: 1 2 3 4 5 6 7 8Over 100 million media files online, search for anything you want! No time limits, no per download fees, no bandwith or content limits.
Registry Cleaner and Optimizer
Registry Fix can Restore & Clean Up Windows Registry Files, Repair DLL Error Messages and Fix General Protection Fault Errors. Does your PC crash, is your system running slow? Get your free system scan now!
or excess chemicals affecting the reaction.
Following these adaptations, my method provides little, if any, chance of obtaining inaccurate results if I carry out the investigation properly. As a result, I will be able to draw extremely clear and accurate conclusions.
Final Investigation
This is how I plan to set up my experiment.
Method:
1) Collect the equipment listed above.
2) Place the card with a large black ‘X’ on, underneath the conical flask.
3) Pour sodium thiosulphate into burette, and measure out 50cm³ into the conical flask.
4) Measure out 5cm³ of hydrochloric acid.
5) Add hydrochloric acid to sodium thiosulphate and swirl conical flask.
6) Start stopwatch.
7) Watch the ‘X’ at the bottom of the conical flask, and stop timing when solution becomes cloudy and opaque and you can no longer see the ‘X’.
8) Record the time.
9) Repeat this experiment so you have 3 readings.
10) Repeat steps 1-9, decreasing concentration each time. [This is done by diluting the solution accurately].
11) Calculate the rates of reaction for each of the timings that you have, and then work out average for each concentration.
12) Use average results to plot onto a graph and draw conclusions from.
I feel that my method is good because I will accurately be measuring only one variable, and maintaining a consistent and fair test, with controlled factors. I am also going to use equipment, and collect data to a suitable and appropriate complexity, so that I can obtain highly precise results and an educated conclusion.
Collecting my results
Concentration/M Time/secs Rate of reaction
1.0M [1st results] 33.44 2.99
[2nd results] 35.85 2.79
[3rd results] 41.97 2.38
[Average results] 37.09 2.70
0.8M [1st results] 36.42 2.75
[2nd results] 36.78 2.72
[3rd results] 45.18 2.21
[Average results] 39.36 2.54
0.6M [1st results] 39.05 2.56
[2nd results] 42.04 2.38
[3rd results] 46.00 2.17
[Average results] 42.36 2.36
0.4M [1st results] 47.34 2.11
[2nd results] 45.81 2.18
[3rd results] 50.68 1.97
[Average results] 47.94 2.09
0.2M [1st results] 60.77 1.65
[2nd results] 78.93 1.27
[3rd results] 83.53 1.20
[Average results] 74.41 1.34
0.0M [1st results] n/a n/a
[2nd results] n/a n/a
[3rd results] n/a n/a
[Average results] n/a n/a
Conclusion
As you can see from my results, and the graph that I have created, there is a clear curved line of best fit showing a constant increase in rate of reaction. The gradient of this line tends to represent a positive correlation meaning that one factor causes the other to change. In this case, as the concentration of the hydrochloric acid was increased, the rate of reaction increased. This is because there will be more particles of hydrochloric acid when it is more concentrated, meaning that there will more collisions of reactions. As a result, the rate of reaction is sped up.
My average results consistently fall within my error bars, showing that I have recorded my results accurately and that I have kept the investigation fair throughout. Generally, I had no anomalies in my results
Last 5 comments…
There have been no comments posted for this article, but you need to register if you want to be the first!