Rates of Reaction

I will use volumes of: 50cm of sodium thiosulphate with no water, 40cm of sodium thiosulphate with 10cm of water, and so on down to 10cm of sodium thiosulphate with 40cm of water. Then, I will draw a cross on a piece of paper with a black pen, and place it underneath a conical flask. Into the conical flask, I will pour the 50cm of sodium thiosulphate solution and 5cm of hydrochloric acid, and start the stop clock. When the mixture has become opaque, that is to say, I cannot see the cross underneath the conical flask, I will stop the clock and record how long it has taken to reach this stage. I will repeat this for each concentration, making sure that the conical flask is fully washed out, because I will be using the same flask every time, so that the flask does not introduce any new variables into the results. To find a rate of reaction from the results I will collect, I will divide 1 by the time in seconds (to make it inverse). This provides me with directly comparable rates of reaction, because as the time gets longer, the rate (the time inverted) is much slower, I will also create 2 more inaccurate graphs showing the results with a line of bets fit. I will repeat the whole experiment twice, in order to reduce the effects of any freak results which may occur, by using averages to make a conclusion. To make the experiment safe, I will be wearing goggles at all times, in case something unexpected occurs. I will be washing my hands regularly and thoroughly washing the equipment before each reaction to make sure that it is as fair a test as is possible with the equipment available.
             Diagram.
             Variables.
             Other variables which may affect the outcome of this experiment, if not kept constant, are as follows:.
             Temperature Of Sodium Thiosulphate - I believe that the hotter the temperature, the faster the rate of reaction. This is because when a substance is heated up, each particle has more energy, resulting in more collisions between the free moving particles in a liquid, causing more particles to react, therefore increasing the overall rate of reaction.