Chemistry Coursework: Rates of Reaction

Authors Avatar
Chemistry Coursework: Rates of Reaction

By Robert Stokoe -11CJ

November 2001

PLAN

Aim

The aim of my investigation will be to explore the effects that the concentration of hydrochloric acid will have on the amount of carbon dioxide produced when it reacts with calcium carbonate. The reaction rates will tell me how fast the chemicals are reacting with one another. I must consider the factors that may affect my testing.

Background Information / Fair test

I will take the necessary steps to keep the room temperature at a constant level. I want keep this at a constant because I know that all molecules are affected by changes in temperature. When temperature is increased it gives the molecules more energy and they move around a lot faster. There is always a drastic increase in movement of the molecules that are given more energy. When the temperature is increased by 10 degrees Kelvin it causes the temperature to double, when increased by 20 degrees it quadruples. The increase in temperature will not only make reactions occur faster but make them more violent as the molecules have extra energy to dispose of. (See figure 1 for further information). I will keep the room temperature constant by performing my experiments in a laboratory with air conditioning.

I will take the necessary precautions to keep the surface area of the pieces of marble approximately the same. The differences in surface area will alter my results if they are not kept at roughly the same size. A large piece of marble chip will have a smaller surface area than of four pieces that weigh the same as the large piece in total.

The greater the surface area the higher the chance of collision and therefore the higher the chance of reactions as there is more room for the reaction to take place. (See figure 2 for further information). If time allows I may experiment with crushing the marble to see its effects on the experiment.

I will take the correct steps to ensure that there are no catalysts in the reaction, as I know that it will affect my readings. Catalyst work by altering the number of phases a reaction has to go through. Most catalysts are used to speed up a reaction. If the number of steps is reduced then the reaction will be faster. I will attempt to eliminate any catalysts by cleaning all equipment before each new experiment.

I will base my prediction around the theory on how concentration will affect the speed of the reaction. The concentration of my solution will be the only thing that is altered through out the entire investigation. The concentration is the number of acid molecules in a given volume. The greater the concentration of acid molecules the faster and more violent the reaction will be. (See figure 3 for further information).
Join now!


To understand my investigation I must first understand how these reactants affect each other and how the theories behind them combine to form the Collision Theory.

The theory states that when particles collide with sufficient energy they react exothermically. At a higher temperature collisions are more frequent and they also have more energy, both because particles are moving faster. At a higher concentration collisions are again more frequent, as there are more reactant particles in the liquid. Increasing the surface area of the solid again increases the frequency of collision between reacting particles, as the liquid reactant ...

This is a preview of the whole essay