Investigation: How does the concentration of acid affect the rate of reaction? :: GCSE Chemistry Coursework Investigation

Investigation: How does the concentration of acid affect the rate of reaction? The aim of this investigation is to test how concentration affects the rate of reaction. My prediction for my investigation is that the higher the concentration, the faster the reaction will be. My reason behind my prediction is: Â · The higher the concentration, the more particles there are which will collide with enough energy to overcome activation energy, which is explained as the collision theory. Collision theory explains how chemical reactions occur and why rates of reaction differ. For a reaction to occur, particles must collide. If the collision causes a chemical change it is referred to as a fruitful collision. For a reaction to occur, the reactant particles must collide. Only a certain fraction of the total collisions cause chemical change; these are called successful collisions. The successful collisions have activation energy at the moment of impact to break existing bonds and form new bonds, resulting in the products of the reaction. Increasing the concentration of the reactants and raising the temperature bring about more collisions and therefore more successful collisions, increasing the rate of reaction. When a catalyst undergoes collision with the reactant molecules, less energy is required for the chemical change to take place, and hence more collisions have sufficient energy for reaction to occur, therefore the reaction rate increases. The four factors that influence the rate of reaction and therefore the experiment are: 1. The temperature. This is because; if the concentration is warmer, then the reaction rate may increase or decrease depending on temperature. 2. The Catalyst. This is because; if the catalyst is of a larger volume or size than the concentration then it may have an affect on the concentration and experiment that will differentiate results. 3. The concentration. This is a variable that will be used because we are trying to find if the concentration will affect the rate of reaction. 4. The surface area. This is because; if the surface areas of the calcium carbonate pieces are different then it will affect the results also because it will give off more gas, the greater the surface area. To achieve the most accurate of results possible I will use all sufficient equipment and data. For my prediction, that the higher the concentration, the faster the reaction rate, I will use pre-test results to help with my evaluation before I start my investigation. Before I started my investigation, I did a pre-test experiment that helped me to reach my prediction.