From the simulation program
The reaction I simulated was:
HCL + CaCO3
This is very similar to magnesium and sulphuric acid because it is an acis and a metal.
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Firstly I tried it with 1.00g of CaCO3 and 25cm2 0.2M HCL. The results show how mush gas is produced:
5 seconds - 1ml 35 seconds - 7.2ml
10 seconds - 2.1ml 40 seconds - 8.1ml
15 seconds - 3.2 ml 45 seconds - 9ml
20 seconds - 4.2 ml 50 seconds - 9.9ml
25 seconds - 5.2 ml 55 seconds - 10.8ml
30 seconds - 6.2 ml 60 seconds - 11.6ml
- Then I tried it with 0.4M
5 seconds - 2.2ml 35 seconds - 14.2ml
10 seconds - 4.3ml 40 seconds - 16ml
15 seconds - 6.4ml 45 seconds - 17.7ml
20 seconds - 8.4ml 50 seconds - 19.5ml
25 seconds - 10.4ml 55 seconds - 21.1ml
30 seconds - 12.3ml 60 seconds -22.7ml
- Then I tried 0.6M
5 seconds - 3.8ml 35 seconds - 20.9ml
10 seconds - 6.5ml 40 seconds - 23.6ml
15 seconds - 9.6ml 45 seconds - 26.1ml
20 seconds - 12.5ml 50 seconds - 28.6ml
25 seconds - 17.4ml 55 seconds - 31ml
30 seconds - 18.2ml 60 seconds -33.3ml
- Then with 0.8M
5 seconds - 4.4ml 35 seconds - 27.5ml
10 seconds - 8.6ml 40 seconds - 30.9ml
15 seconds - 12.1ml 45 seconds - 34.1ml
20 seconds - 16.6ml 50 seconds - 37.3ml
25 seconds - 20.8ml 55 seconds - 40.4ml
30 seconds - 24ml 60 seconds - 43.3ml
- Finally with 1M
5 seconds - 5.4ml 35 seconds - 33.9ml
10 seconds - 10.7ml 40 seconds - 37.9ml
15 seconds - 15.7ml 45 seconds - 41.9ml
20 seconds - 20.5ml 50 seconds - 45.7ml
25 seconds - 25.1ml 55 seconds - 49.3ml
30 seconds - 29.6ml 60 seconds - 50+ ml
Prediction
I predict that the higher the concentration of sulphuric acid the faster the rate of reaction will be. This is because in my experiment on the computer the results showed exactly that. The explanation for the higher rate of reaction is because the solute (in the case of HCL + CaCO3 it would be HCL) reacts with the magnesium. The more solute there is then the faster the reaction will happen because the are more particles to collide so there will be more effective collisions where bonds are broken and made. This is more easily explained in a diagram.
Less Solute = Slower reaction More Solute = Faster reaction
Results
1 Molar Sulphuric Acid
3cm Magnesuim ribbon
Results
0.8 Molar Sulphuric Acid
3cm Magnesuim ribbon
Results
0.6 Molar Sulphuric Acid
3cm Magnesuim ribbon
Results
0.4 Molar Sulphuric Acid
3cm Magnesuim ribbon
Results
0.2 Molar Sulphuric Acid
3cm Magnesuim ribbon
Conclusion
I found that the higher the concentration of acid the faster the reaction finished.
I think that this is because There are more acid particles in the solution which means there will be more effective collisions thus increasing the rate of reaction. There are more effective collisions because if there are more solute particles then the particles will be colliding more frquently. If there are more collisions in a shorter space of time then the same percent will be effective collisions but there will be a higher frequency of effective collisions as there are more collisions. This is proved by my results. This means that my prediction was correct.
Evaluation
Overall the experiment went well, however I had one or two anomalous results but most seemed close to the average. What should have happened in the experiment was that an equal amount of gas was produced each time because I used the same amount of magnesium. Infact the amount ranged from 34cm3 to 53cm3 this is because when I cut the magnesium ther may have been small differences in the length. Another reason is that in one lesson I used very old magnesium that looked like it had half reacted and in another lesson I used new, shiny magnesium meaning that there would be less particles to react and produce gas so thee would be less gas. Also the gas syringe is not perfect and it takes quite a bit of gas to ove it so it moves in steps.another reason is for 0.2 molar acid I didn’t use a gaas syringe as the experiment took so long I had to do 2 at the same time. The last reason is how far I pushed the bung into the top of the conical flask as this pushed air into the gas syringe.Bearing that in mind the results were all quite close to the average.
If I was to do the experiment again I would note down the temperature of the acid before I put the magnesuim in as temperature is a different variable. I would also use only shiny magnesium and take care in measuring it. I would leave lots of time to do the experiment and measure the concentrations of acid more carefully.
