What Affect Does Concentration Have On the Rate of a Chemical Reaction?

Apparatus

Goggles Beakers Measuring cylinder Pipette

Stop watch Solutions Paper

Fair test

To make this experiment a fair test we kept the total volume the same as if we didn't the results would be to varied and no conclusions could be made. We kept the volume of the Hydro Choleric acid the same throughout the experiment as the whole idea of the experiemt was to see what affect concentration has on the rate of the reaction.

Variables

For this experiment we kept the same amount of Hcl in to make the experiment fair the variables were the sodium thio sulphate and the water. We controlled the variables by measuring them out accurately each time and making sure we didn't mix any of the to before hand to make it a fairer test. We did this by washing the pipette out after each time we had used it.

Equation

Na + S O (aq) + Hcl (aq) Na Cl (aq) + H 0 (I) + SO (g) + S (s)

Conclusion

I conclude from the graphs the more water that is added the more time it takes for a reaction to occur (go cloudy). I feel that these results are correct due to the collision theory, which states that for a reaction to take place particles have to collide, and with enough energy. Because of this I feel that I have proved my prediction to be correct which was, that by increasing the concentration the quicker the reaction will be. Meaning that the less sodium thio sulphate the less particles which means that it will take longer for a reaction to take place.

Evaluation

I feel that the experiment went well. I felt that our results were fairly accurate as you can see from my graphs but because I rounded up the time to the nearest second my results could be slightly out. The equipment I worked with was good and I did not have any problems with it. To improve this experiment I believe that we would need to repeat the experiment a few more times to make our results more accurate. But I do feel that the results obtained show enough evidence for my conclusion. I believe that my experiment worked and if I did it again then I would spend more time getting more results to make it more accurate.