To see how much carbon dioxide can be measured depending on the size of marble chips used

PROBLEM

A manufacturer wants to start making carbon dioxide on a commercial basis by reacting marble chips with hydrochloric acid. He wants to find out;

What factors will affect the rate of this reaction
How much carbon dioxide he will obtain when 400 tonnes of calcium carbonate is reacted in an excess of hydrochloric acid.

INTRODUCTION/AIM

The aim of this investigation is to see how much carbon dioxide can be measured depending on the size of marble chips used. When combined with hydrochloric acid, Carbon dioxide gas is given off, and in this investigation I am measuring rates of reaction.

PRELIMINARY INVESTIGATION

The rate of reaction depends on how often and how hard the reacting particles collide with each other. Particles have to collide in order to react, and the have to collide hard enough as well. This is called the collision theory. When the temperature is increased the particles all move quicker. If they are moving quicker then they are going to have more collisions. Higher temperature also increases the energy of the collisions, because it makes all the particles move faster. Faster collisions are only caused by increasing the temperature. Reactions only happen if the particles collide with enough energy. Ata higher temperature there will be more particles colliding with enough energy to make the reaction happen. This initial energy is known as the activation energy, and it is needed to break the initial bonds. If one of the reactants is a solid then breaking it up into smaller pieces will increase its surface area. This means the particles around it in the solution will have more area to work on so there will be more useful collisions. A catalyst works by giving the reacting particles something to stick to where they can bump into each other. This obviously increases the number of collisions too. If the solution is made more concentrated it means that there are more particles of the reactant moving between the water molecules which makes collisions between the important particles more likely. Because of this I expect the reaction rate to be quicker when the concentration of the acid is higher. The reaction should however, end on the same amount of gas given off.

Rate increasing with concentration

Rate increasing with temperature

Rate increasing with surface area

PREDICTION/JUSTIFICATION

What I think will happen

The volume of carbon dioxide collected at intervals will take longer depending on the size of the marble chips. The smaller the chips, the more gas collected at each one minute interval.

Why I think this will happen

The smaller the chips, the greater the surface area, and so they take less time to break down and give off gas, therefore increasing the chance of a successful collision.

In order to ...