Rates of Reaction :: GCSE Chemistry Coursework Investigation

Whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon. I want to find out whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon. Variables There are two important independent variables in my investigation the first of which is the concentration of the Hydrochloric Acid used during the investigation. The concentration of the acid will partly determine how fast the reaction takes place, if we put some of the magnesium ribbon into the HCL at 2molar then it might have simply dissolved within a few seconds and then I would not have had time to record down any decent enough results to plot a graph with. The other important independent variable that will affect the speed of the rate of reaction is the length of magnesium ribbon. We need to put enough Mg Ribbon into the HCL so that it doesn’t run out straight away but also so that the experiment stops by itself once the gas syringe has filled up. The reasons for choosing these two independent variables are that it would be too hard to try and find a catalyst for this experiment; a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction. Finding a catalyst for this particular experiment could take months never mind the amount of time we have been given for our experiment. The independent variable that I will change is going to be the hydrochloric acid, we will use 50ml of HCL at the following molarity concentrations; 2molar, 1.6molar, 1.2molar, 0.8 molar and 0.4 molar. I have decided to experiment with these different strengths of molar because I think it will give a wide set of results to put into a graph. The dependant variable I shall be measuring will be the time it takes for the magnesium to completely react with the hydrochloric acid, I shall record the times for each concentration of hydrochloric acid three times so that it makes it a fair test. To ensure the investigation is fair we will use the same length of magnesium ribbon for all the different strengths of hydrochloric acid and the length will be the one that we picked out from the preliminary experiments. Another way in which we will keep the investigation fair will be to carry out an experiment at each concentration of hydrochloric acid three times so that we can then get hopefully around the same outcome from each experiment, and if there are any anomalies we can try to explain why they happened.