Aim: The aim of my investigation is to find precisely how changing the acid concentration affects the rate of reaction between calcium carbonate and hydrochloric acid.
Prediction: I predict that as concentration increases so will rate of reaction. I think they will be directly proportional. This is because if a solution is more concentrated it will have more particles of the reactant moving in it. This means the more of a reactant in the solution the more likely it is to bump into other particles, as they are crowded together. If you double the concentration you will double the reactant, which will double the number of collisions, and so will double the speed of the reaction.
Background knowledge: .
In this experiment there were several variables. .
They were:.
Temperature.
Pressure.
Surface Area.
Concentration.
In any investigation it is important to keep all variables constant except one, which you may be testing. In my investigation I will only vary concentration. I will make sure the other variables will remain constant. .
Temperature: .
Temperature affects rate of reaction. As temperature increases so will rate of reaction. In most reactions for every 10oC rise in temperature will double the rate of reaction. This is because the particles have more kinetic energy, which means they move faster so they are more likely to collide with each other. The particles will also have more energy when they collide. This means that when particles have more energy than the activation energy they have more chance to react as they have more energy. This is known as the collision theory. The diagram below shows the movement of particles in two extremes of temperature. The graph below shows that the increase in temperature leads to a clear increase in rate of reaction.
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Concentration: The concentration of a solution may increase the rate of a reaction. This is because if a solution is more concentrated it will have more particles of the reactant moving in it.