The Effect of Temperature on the Rate of Reaction :: GCSE Chemistry Coursework Investigation

The Effect of Temperature on the Rate of Reaction Plan We must produce a piece of coursework investigating the rates of reaction, and the effect different changes have on them. The rate of reaction is the rate of loss of a reactant or the rate of formation of a product during a chemical reaction. There are five factors which affect the rate of a reaction, according to the collision theory of reacting particles: temperature, concentration (of solution), pressure (in gases), surface are (of solid reactants), and catalysts. I will investigate the effect temperature has on a reaction. Aim To investigate how a change in temperature effects the rate of a chemical reaction. The reaction that will be used is: Sodium Thiosulphate + Hydrochloric Acid --> Na2S2O3(aq)+ 2HCl(aq) Sodium Chloride + Water + Sulphur Dioxide + 2NaCl (aq)+ H2O(l)+ SO2 (g)+ Sulphur-S (s) Prediction I predict that as the temperature is increased the rate of reaction will increase. This means that the graph drawn up in my analysis will have positive correlation, and will probably be curved as the increase in rate of reaction will not be exactly the same as the temperature is increased. This can be justified by relating to the collision theory. When the temperature is increased the particles will have more energy and thus move faster. Therefore they will collide more often and with more energy. Particles with more energy are more likely to overcome the activation energy barrier to reaction and thus react successfully. If solutions of reacting particles are made more concentrated there are more particles per unit volume. Collisions between reacting particles are therefore more likely to occur. All this can be understood better with full understanding of the collision theory itself: For a reaction to occur particles have to collide with each other. Only a small percent result in a reaction. This is due to the energy barrier to overcome. Only particles with enough energy to overcome the barrier will react after colliding. The minimum energy that a particle must have to overcome the barrier is called the activation energy. The size of this activation energy is different for different reactions. If the frequency of collisions is increased the rate of reaction will increase. However the percent of successful collisions remains the same. An increase in the frequency of collisions can be achieved by increasing the temperature, concentration, pressure, and surface area. Also I predict that if the temperature is doubled, then the time taken for would be more than half because not only would the particles be moving faster to create more collisions, but they would also have more energy so there would be more successful collisions