Factors Affecting Rates Of Reaction.

Also, as the strength of the acid increases, the particles will have more activation energy. So with more particles available to react and the particles having more energy there are likely to be a lot more collisions in turn more individual reactions between particles and therefore a faster rate of reaction.

List of Apparatus

Conical Flask

Delivery Tube

Bowl of Water

Measuring Cylinder

Stopwatch

Weighing Scales

Beaker

Marble Chips o Block and Powdered Form

2 molar, Hydrochloric Acid

What I Will Measure

Every ten seconds for two minuets I will measure the amount of gas collected in the measuring cylinder.   

What I Will Alter Between Measurements

Between each measurement I will alter the molarity of the acid ranging from 0.5 to 2.0 molar with intervals every 0.5 molars .

To Make the test fair I will keep these things the same

The things that will remain the same all the way through the experiment are:-

The Mass of the Chips

Amount of Acid

Temperature of Reactants

Equipment Used

Units of Measurement

Method of Measurement

And as much as I can the size and surface area of the marble chips

How I Will Keep My Experiment Safe

I will make my experiment safe by taking extra care with the concentrated acid and not standing too close to the experiment in case the reaction is more violent than expected. Also the usual lab safety precautions/rules    e.g. wearing goggles and tucking in loose clothing etc.

Plan

First I will gather the equipment and set it up as shown in diagram A. To collect the gas I will set up the bowl of water and completely submerge the measuring cylinder, stand it upright in a clamp stand and place the delivery tube from the conical flask to the underneath of the upturned as shown in diagram B.

Once the equipment is in place I will measure out 30 ml’s of 0.5 molar acid and pour it into a conical flask, then weigh out 25 grams of equally sized (as much as possible) marble chips and add them into the conical flask then inserted the bung.

As the reaction is taking place the gas given off (CO2) will travel along the delivery tube and into the upturned measuring cylinder pushing the water down the graduation mark giving me an accurate reading of how much gas has been given off.

I will take a reading of the gas given off every 15 seconds as this is most practical for all of the strengths of acid. I will take a reading every 15 seconds until the measuring cylinder has reached its capacity.

Once the result is recorded I will empty and rinse out the conical flask, weigh out another 25 grams of the same sized chips as before (again as much as is possible) and repeated the experiment 3 more times but each time using a stronger strength acid starting from the original 0.5 molar to 1.0 , 1.5 and finally 2.0 .  

Then I will repeat the experiment with each molar acid two more times giving me three sets of results so I can find the average result giving a much more accurate and reliable result and hopefully removing as many anomalies as possible.  

Conclusion

 My results prove my hypothesis. They show that the higher the concentration of the acid the quicker the rate of reaction. The results also show that the research that I did also showed to be correct. If my results had been more accurate I think the results would show the concentration of the acid and the rate of reaction to be directly proportional.

The graph also supports my prediction. On the graph, the steeper the curve is, the faster the rate of reaction. Also from the graph I was able to work out the average rate of reaction for the gas produced.

           

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 hypothesis. To make the overall experiment results more accurate we repeated it three times and then took the average.

If I was to do this experiment again I would probably make it more accurate by using a Burette (A burette is a vertical cylindrical piece of  with a volumetric graduation on its full length and a tap on the bottom http://en.wikipedia.org/wiki/Burette) to measure the amount of gas given off, this would measure a lot more accurately.

Also other things that I would like to investigate would be the experiment of time against amount of gas produced to show at which points the rate of reaction was at best and the curve/line of reaction. I would like to also investigate other factors, which affect the rate of a reaction like temperature and surface area to see how they affect the rate of a reaction.

Some other areas in the experiment that I feel I could have improved on were factors like, controlling the stopwatch. There is lots of room for improvement on human error here. But the inaccuracies due to them were minimal because I paid close attention to them during the experiment.