An experiment to find out how changing the concentration of acid :: GCSE Chemistry Coursework Investigation

An experiment to find out how changing the concentration of acid affects the rate of reaction Planning Aim: I am to find out how changing the concentration of the hydrochloric acid (HCL) affects the rate of reaction. The hydrochloric acid will be reacting with marble chips (small, medium, large). During my experiment I will be changing one variable. This will be the concentration of the acid. I will use the concentration of HCL from 0.5 molar/dm3 to 3.0 molar/dm3. I will use 3grams of marble chips for every size of chip. By doing this I will find out if the rate of reaction is quicker or slower using a different concentration of acid. The equation I will be using is: CaCO3 (s) + 2HCl (aq) CaCl2 (aq) + H20 (l) + CO2 (g) Calcium Hydrochloric Calcium Water Carbon Carbonate Acid Chloride Dioxide Method Firstly I must get the correct equipment and assemble it safely and correctly. To do this I will fill a water tray half full with water. Then I will collect 3g medium chips. I will measure 30cm3 of hydrochloric acid. I will connect the delivery tube to the measuring cylinder which is turned over which will be full with water. This is shown on my diagram. I will begin timing using a stopwatch and record the results every 10 seconds for 1 minute. I will use 0.5molar/dm3 to 3.0molar/dm3 of hydrochloric acid and record 3 sets of results and then I will take an average. Fair Test In order to make my experiment safe I will change only one thing. I will be changing the concentration of the acid. Everything else will remain the same through out the experiment. I will use the same equipment and do the experiment during the same lesson where I can. This can be important because room temperature can increase the rate of reaction. The temperature could be higher on a certain day and affect my results. Background Information Rates of Reaction * Increasing the temperature increases the rate of a chemical reaction. * Some chemical reactions are fast and others are slow. A fast reaction could be a rocket exploding, and a slow reaction is metal rusting. * Rates of reaction can be measured by finding out how quickly a product is formed or how quickly a reactant is used up. * Examples of measuring reaction rates include measurement of the volume of gas formed, and measurement of the loss in mass when a gas is given off. How does surface area affect a chemical reaction? If one of the reactants is a solid, the surface area of the solid will