Rate of reaction

3. Surface area- If a solid or a solid catalyst is broken down into smaller pieces the rate of reaction increases. Therefore, there is more chance that a reactant particle will hit the solid surface and react. The increase in speed happens due to the smaller pieces of the same mass of solid have a greater surface area when compared to larger piece of a solid.

4. Catalysts- A catalyst is a material/chemical which speeds up a chemical reaction without being used up itself. If a solid catalyst is broken down into smaller pieces the rate of reaction increases. Catalysts are used to save money and allow materials to be made faster and therefore more cheaply.

Reactions can only occur when the reactant particles collide; most collisions aren’t successful in forming new molecules. In my previous experiments, I found that if the acid was stronger, then there are more acid particles so the rate of reaction would increase. Increasing the heat, meant the particles would be moving more vigorously, and would start to crash and break. An increasing in the surface area meant that there is more of a chance to have a reaction.

My prediction

The time taken for the magnesium will decrease as the concentration of the hydrochloric acid is increased. The more concentrated the acid is will increase the chance of collisions increasing. I have made this prediction from the information I collected about the collision theory.

Variables

I this experiment, I am going to be altering the concentration of the hydrochloric acid by diluting it with water.  I will use a stopwatch to measure the time taken for the magnesium to react with the hydrochloric acid. To make this a fair experiment I will keep the length of magnesium the same length (1cm), the volume of acid and water at 50mls throughout and I will keep the temperature the same throughout as well (room temperature).

*The charts were then completed by filling in average time*

Practical Procedure

1. Collect the apparatus

29890084. Measure 50cm of hydrochloric acid into a flask and add into the burette and pipette

29949036. Measure 1cm of magnesium  with a ruler, then clean it with steel wool

29949124. Add the magnesium to the hydrochloric acid and take the time taken for the magnesium to react by using a stopwatch. You then record the time, empty the flask out and wash it out

29888584. Add 45cm of acid to the burette and add 5cm of water to dilute it

29886056. Repeat this procedure but by adding 5 cm of water each time and taking away 5cm of acid each time

Safety Procedure

1. Beware of acid which is corrosive

29920496. Wear safety glasses

29920540. Start experiment in a well ventilated area

Interpretation

∙        As the concentration increases on the time taken graph the time decreases.

∙        The graph differs from 102’s at 25/25 to 22s at 50/0.

∙        As the concentration increases on the rate graph the rate increases.

This agrees with my prediction. If the concentration is at 25/25 and it took 25s for the reaction to occur and then you double the concentration to 50/0 so it would take half the time because there are more particles colliding with each other.

The time graph has a smooth curve this is shown on the graph following this page. The rate however has a straight line.

Evaluation

First I collected all of my equipment which was given to me by my teacher; I then collected information from the task and was therefore able to write a report on the project. I corrected myself and wrote out a sheet to guide me, step by step, through the experiment. After completing the experiment, I wrote out a final sheet of results and drew out two scatter graphs and rechecked my results to make sure everything was in order and all made sense. When the experiment was completed, I looked over the results and the experiment was a success.