Chemistry

In my experiment I am going to find out how increasing the temperature of the hydrochloric acid and sodium Thiosulphate solutions affects the rate of reaction when they are mixed together, I am doing this as I want to see if the temperature has a large or small effect, and why this is.

Hydrochloric acid + Sodium Thiosulphate -->Sodium Chloride + Sulphur dioxide + Sulphur + Water
2HCl (aq) + Na2S2O3 (aq) --> 2NaCl (aq) + SO2 (g) + S (s) + H2O (l)

Preliminary

I did a preliminary of my experiment to check it would work and to make sure my hypothesis can be tested fairly and accurately.
For the preliminary, I decided to measure the amount of gas produced in two minutes as a product of the reaction dependant on the temperature. To keep the test fair the changes in the temperature were spread out equally and the only independent variable I used was the change in temperature, the only dependant variable was the amount of gas produced in a controlled amount of time (2min). I kept all other variables; volume, time solutions were left to react, amount of time solutions were left to be heated, concentration, amounts of solutions, amount of times solution was mixed during reaction, amount of chemical used and amount of water in water bath, were all controlled. If I didn’t do this it wouldn’t be a fair test, for example, if I also had dilution as an independent variable in the experiment, the results wouldn’t show both the affects of temperature and dilution, which would make the results inaccurate.

The method:
  1. I filled a tray with water and set up the conical flask with a cork attached to a delivery tube on the top. This is used to keep the gas inside the flask, to travel through the tube to a measuring cylinder I will attach later to measure the gas produced.
  2.   I used measuring cylinders to measure 50cm³of sodium Thiosulphate and 10cm³ of hydrochloric acid and set up a Bunsen burner with a beaker filled with water on top; this will act as my water...