How does concentration affect the rate of reaction between Sodium Thiosulphate and Hydrochloric acid.

Solutions provided
Sodium Thiosulphate 40g/l
Hydrochloric acid 73g/l
Planning
How will we time the reaction?
We will put the solution on top of the cross and add the chemicals together. At this point, start the stopwatch. The solution will begin to go cloudy. You should stop the watch when you can no longer see the cross.
What variables do we need to control?
We need to control the temperature, this should be room temperature. We need to make sure the volume of the acid is 10 cm3 and that the volume of Sodium Thiosulphate is 50 cm3. We will need to use the same cross every time and that…