My aim is to find out how long it takes for magnesium to react using different concentrations of acid.

Anil Khetani

Aim ~

Hypothesis ~

I predict that as the acid gets weaker the rate of reaction will get slower and slower. I think this because as the acid gets less concentrated the magnesium will have less to react with so it would take longer to react where as if the acid was more concentrated the magnesium would have more particle of the acid reacting with it so it would break down much quicker. For example if some builders wanted to break a wall down and only one builder was trying to break it down, it would take him/her longer to break the wall down but if there were five builders they would be able to break it down much more quicker as the builders would have there own part to break down rather then one builder having to break the whole wall down. There were other factors that I could have chosen to vary but I chose to keep them the same through out the whole experiment, they are:

Pressure
Surface area
Temperature
Catalyst

I chose to keep the pressure the same as I thought by experimenting on the pressure I would not get perfect results. For pressure I would need to make sure that I was able to get all the gas in the flask, so I would need to stop all the gas getting out but as soon as I would put the magnesium in the acid gas would start to give off and there would be no way for me to keep all the gas in the flasks by using the equipment available. If I did not keep the pressure the same I would find that when there is more pressure the reaction will be quicker as the particles have less space to move so they would collide more. I chose not to do the surface area as I would not be able to get an accurate measurement for the surface area because there would be no way I could measure all the reactant and get an accurate measurement, for the same reason I chose not to do catalyst. If I did not keep the surface area the same I would find that if the surface area was smaller the reaction would be quicker, as the acid would have less to react with. I did not do temperature for no particular reason, I chose from the strength of the acid and the temperature and I thought that I would get better results by varying the strength of the acid. If I do not keep the temperature the same I would find that as more heat would be applied the reaction would be quicker this is because the particle would get heat energy which would get converted into kinetic energy which would make the particle collide with the reactant more. The factor that I chose to change was the concentration of the acid, I will do this by measuring the molar of the acid that shows the concentration of acid. To make the experiment fair I will keep the pressure on the reactant the same I will do this by not putting any pressure on any part of the experiment. I will keep the surface area the same by measuring each piece of magnesium the same, this is how I will be able to keep the surface area as similar as possible using the equipment available. I will keep the temperature the same by doing the experiment in room temperature and in the same place. I will repeat the experiment three times and then average the results out which will give me the average speed and time of the reaction, I will do this for all the different strengths of acid that I use. If I find that one of my results does not fit in with the rest of the experiment I will investigate why it went wrong and correct that result. I will use the same acid for each strength, so I will not change the acid after using it once I will use it three times. I will thoroughly wash all the equipment out after using it once so it would be clean and not contaminated when I go on to the next part of the experiment.