Ben Woodward
Chemistry coursework
Investigating the rate of reaction between magnesium and hydrochloric acid
Aim In this experiment I aim to investigate the rate of reaction between magnesium and hydrochloric acid. This reaction rate will be affected by different variables, which can be changed; these are Temperature of the hydrochloric acid, mass of magnesium and concentration of the hydrochloric acid. Others things can effect the reaction rate but these are the main variables. In this experiment I will only alter one of the variables and keep the rest at a constant rate. For this experiment I will concentrate on the concentration of the hydrochloric acid and see what the effects are on the rate of reaction when this is altered.
Prediction I predict that the higher the concentration of the acid the quicker the reaction time I no this because, “rate plus concentration are directly related” (Salter’s A-level chemistry second edition chapter 10). This tells me that the concentration will directly affect the rate of reaction. To back this prediction up I have to look at the collision theory, this states that for the two different reactants to react the particles of each have to collide and hit each other hard enough so that it is possible to create enough energy for the to particles to break or form new bonds with the other particles this is called a successful collision. When there is not enough energy for the particles to hit each other hard enough to react then they will simply bounce of each other this is called an unsuccessful collision. When the concentration is higher then this means there are more acid particles in there meaning there will be more collisions between the magnesium particles and the hydrochloric acid particles. When there are more collisions then there tends to be more successful collisions between the two different reactants. I found this out using ‘Co-ordinated science chemistry by Gallagher and Ingram’ where a diagram of a similar experiment is shown on the diagram below,
