I am going to investigate how a change in concentration affects the reaction rate between Sodium Thiosulphate and Hydrochloric acid. The chemical equation for the experiment is as below;
Na2S2O3 + 2HCl 2NaCl + H2O + S + SO2
Ã˜ When pouring the acid, make sure it is done above eye level. Hydrochloric acid is also an irritant, so goggles could be used.
Ã˜ Always wash your hands after doing an experiment, especially ones with irritant.
Ã˜ The reaction gives off Sulphur Dioxide, which is a highly acidic gas, so as soon as the reaction has finishes, it all needs to be washed down the sink with plenty of water.
Ã˜ Two small 100cm3 beakers, for the Sodium Thiosulphate and Hydrochloric acid
Ã˜ A small 100cm3 conical flask to mix the fluids in
Ã˜ A small conical flask that has a capacity of 35cm3
Ã˜ A piece of lined paper, to judge when the reaction has finished
Ã˜ A stop-clock to determine the duration of the reaction
Ã˜ A calculator to work out the average reaction rate
Ã˜ A total of 280cm3 Sodium Thiosulphate
Ã˜ A total of 80cm3 Hydrochloric acid
A pilot study was conducted to see if the reaction being investigated actually worked, and if the amounts and concentrations were effective. The results were as follows;
Vol. Of Thiosulphate Vol. of acid (cm3 Vol. Of water (cm3) Time 1 (s) Time 2 (s) Time 3 (s) Average (s) Rate (s-1)
From these results, I can determine whether the experiment was a success and whether I can learn from my mistakes. All decimals have been rounded up or down to the nearest whole number.
To make the experiment fair, there was only one va