Preliminary experiment-For the preliminary experiment, my aims were;
- To see how much Magnesium gives a reasonable time to react?
- What concentration gives a reasonable time?
- How do I change the concentration?
- Can I repeat the experiment reliably?
I chose to use 2cm piece of magnesium because it seems like a reasonable amount to use. I decided that 40 seconds was a reasonable time because it was a fairly quick reaction, and it wouldn’t take me long to do these experiments in the lessons. I repeated test tube 2 again just to make sure that it wasn’t a one off. The main reason why I needed to do this experiment was to see how I could make the final experiment as fair as I can; here are some improvements that I can make:
- Make sure you start the clock as soon as the Magnesium hits the Acid.
- Swirl the Conical Flask with a steady hand and not too quick.
- Keep your eye on the magnesium so you don’t miss the exact point at which it dissolves.
- Record everything that you notice
- Used distilled water to change the concentration of the Acid
Apparatus-
- Conical Flask
- Beaker
- Measuring cylinder
- Ruler
- Graph Paper
- Stop-watch
- Magnesium
- Hydrochloric Acid
- Distilled Water
Main Plan-
For each experiment I will use 2cm of magnesium ribbon and 2M acid. I will use 25cm of Hydrochloric Acid and when the concentration needs changing I will add Distilled water, because this will give the Acid particles more space to move around and so there won’t be so many collisions/second. When I am measuring the Acid or Distilled Water I will need to put my eyes level with the top of the Acid or Distilled Water so that I can read it accurately off the measuring cylinder. Make sure there are no spillages.
I will start the clock when I drop the magnesium into the solution and hits the Acid. The clock will be stopped when the fizzing/bubbling has stopped and the magnesium has disappeared. Make sure that you don’t take your eyes off the reaction.
To make this experiment a fair test, I will make sure that I use exactly 2cm of magnesium by placing it on some graph paper under it so I can use the squares to read it accurately. I will rub the magnesium ribbon with sand paper so it will get rid of any other particles that could change my results.
Results
Result Analysis-my results show that the higher the concentration then the higher the rate of reaction. All the results in the same concentration are the same time within experimental error. I also noticed that the reaction gave out some heat.
Conclusion-In conclusion, I found out that the lower the ‘M’ Molarity is then the longer the reaction takes, this is because the acid particles are spread out more in the Distilled water, so there are less collisions/second between the magnesium and acid particles. In the graph of Time against Concentration, my point is proved because the curve shows that the higher concentration then the longer the reaction time. My prediction has been backed up by my results that have been found. I didn’t predict that the reaction would be an exothermic reaction, this was a surprise to me.
Evaluation-These results that I obtained were of good quality. You have got to give a little lee-way because of experimental error, but on one of my results I had to repeat it because it was 9 seconds off the closest time, so I could get a better and more fairer average. If I was to repeat this experiment I would do more tests, larger concentrations and different lengths of magnesium. This would widen the range of results and give me a better conclusion. I think that I could of done with a few more concentrations just to boost my conclusion because I’m not too happy with the amount of different concentrations that I have used.