An Investigation into the factors that affect the rate of reaction

iii) Surface area of chips: The larger the size of the marble chips the greater the likely hood of the particles reacting, if the surface area is greater the hydrochloric acid particles are more likely to collide with it therefore increasing the rate of the reaction. This test could be fairly accurate but the size of the chips is fairly inaccurate and could therefore affect the results.

Our experiment:

To investigate the rate of the reaction between hydrochloric acid and marble chips to find the maximum amount of carbon dioxide given off we will use concentration as our variable. We will vary the concentration from 100 % to 20% at intervals of 20%. I will use small size marble chips. The acid will be kept at room temperature.

Equation:

Hydrochloric acid +Calcium carbonate=Carbon dioxide +

HCl + CaCO = CO2 +

Prediction:

I think that the higher the concentration of the acid the faster the carbon dioxide will be produced and given off. I think this because the higher the concentration of the acid molecules the more particles will be available to react with the marble chips. As the concentration increases the more hydrochloric acid particles will be in the solution, this increases the chances of a collision occurring which means that more carbon dioxide will be produced.

Apparatus:

1 test tube, 1 gas syringe, 1 conical flask, 1 bung, 1 stop clock, tubing, hydrochloric acid and marble chips.

Diagram:

Method:

After collecting and setting up the equipment the acid and the marble chips should be weighed or measured out the acid should be put in to the conical flask, then the stop clock should be ready and it is imperative that the gas syringe is pushed back to zero. Then when ready the marble chips should be placed in to the conical flask. As soon as all of the chips are in the flask the timer must be started, the results of the gas being given out must be checked and recorded every 10 seconds. This is obtained by reading from the measurements on the side of the gas syringe.

The results will be recorded and the conical flask will be washed out throughly so that it can be re-used.

Range:

The experiment will be repeated twice to obtain a more accurate average.

Safety:

You will be using concentrated acid; so at all times goggle must be worn. If any spills onto your hands it should be washed off immediately and a lab coat must be worn to protect clothing.

Fair test:

Each time I repeat the experiment I will keep the temperature, surface area of the marble chips, the equipment and the amount of acid/water used the same. These are the other factors, which may affect the results and the rate of reaction.

The only thing that I will change each time is the concentration of the acid.

Results:

Experiment 1:

Experiment 2:

Average:

Graphs of results:

Analysis:

The results that I achieved were very accurate. The results from the two different experiments were helpful and proved my prediction. The results go up by similar amounts each time.

Analysis of graph, the two graphs seem to be very similar which shows that there were no problems in the experiment.

Conclusion:

My results prove my prediction, the higher the concentration of acid the faster the rate of the reaction. This is due to the number of particles in the solution for the reactants to react with.

My graph also proved my prediction further; this is a more visual proving.

Evaluation:

Overall I am pleased with my results and the way the experiment was carried out. I think my results were fairly accurate and proved my predictions. To make the overall experiment results more accurate we repeated it twice times and then took the average (on the graph).

I do not think that there is any thing that I would change in our experiment, I might have repeated the experiment once more for accuracy if there was more time.

I would also like to have had a more accurate means of taking the results and the stopwatch time, as there are inaccuracies that may occur.

Luke Bebb 10AM