Chem Coursework - Investigating the Effect of concentraion on rate of Reaction
...20ml water for 1.2Molar etc.) Preliminary Experiment – Results – Time (seconds) Volume of Gas Produced (cm3) 2.0M 1.6M 1.2M 10 20 30 40 50 60 Prediction – From what I have already done in my preliminary experiment, and from my own scientific knowledge, I predict that as you decrease the concentration, the rate of reaction will also decrease. I know that as you decrease the concentration, there are less particles of HCl in the same amount of space. This, using the collision theory, means that there is a smaller chance that a collision between an HCl particle and a H20 will take place, and therefore the reactions is slowed. I also predict that there will be minor anomalies, as there are many margins for error, such as how much air the bung pushes into the flask. Also, I think that minute differences in the length of the Magnesium will affect the results by changing the total volume of gas produced, as there will be more/less magnesium to be used up. Method – Firstly, the experiment must be safe, and so I will conduct it in a controlled lab, wearing protection and removing any possible dangers from the surrounding area. From the information I gathered in my preliminary work, I have decided to stick with using the same concentrations, but more of them (those being HCl 2.0Molar, 1.6Molar, 1.2Molar, 0.8Molar and 0.4Molar), have 50ml of HCl/H20 solution, and a 4cm strip of Mg ribbon. The reasons I am using these specifications for the experiment is because they worked very well in the preliminary experiment, giving me reliable results, and therefore they should produce clear, reliable results in the real experiment, which is important for the investigation to be accurate and successful. I must also make sure my test is fair. To do this, I will carry the experiment out at one time, so the surrounding environment will not change. Factors like temperature and sunlight can change the rate of reaction, ruining the results. I know this from my own scientific knowledge, that a change in temperature will give the reaction more energy and make more collisions occur. It will also cause the Activation Energy of the reaction be easier to reach. I will use the same equipment, the same concentration of the solution, and the same chemicals. I will repeat any recordings that have possibly been taken in unfair circumstances. 1. 1. Set up the equipment, as in the preliminary experiment. 2. Measure out 50 ml of 2Molar Hydrochloric Acid (HCl) in one of the measuring cylinders. 3. Pour the HCl into the conical flask. 4. Making sure the syringe is fully closed, add 4cm of Magnesium (Mg) ribbon to the HCl, and replace the bung immediately. 5. Record the volume of has produced on the syringe every 10 seconds for 2 minutes. 6. Wash the conical flask and reset the syringe to 0. 7. Repeat steps 1-6, but instead of adding 50ml of HCl, add 40ml of 2M HCl from the same measuring cylinder as used before, a...