Investigating the rate of reaction of Magnesium and Hydrochloric acid

I am going to perform the above experiment by changing certain variables to procure enough results to create a graph and a pattern. There are some variables that cannot be changed, such as room temperature and thickness and length of the magnesium. These would create results that would be hard to interpret. Doing this would create a fair test.

To do is I will first start with 10cm3 of Hydrochloric acid to a piece of Magnesium 1cm long. The Magnesium will then be added and the time taken for it to react completely with the acid will be recorded. On the next experiment there will be 9cm3 of Hydrochloric acid to 1cm3 of Distilled Water. I will continue adding water and lessening the amount of acid and record my findings.

I predict that changing the temperature of the acid would create faster results (if higher temperature). This is because the atoms in the acid will be vibrating more and so will be more likely to collide with the magnesium. If the concentration of the acid were to be weakened I believe that it would take longer for the magnesium to collapse because there will be less Hydrochloric acid particles to collide with the magnesium.

I will need the following equipment:

Ruler (to measure the magnesium)

Beaker

Hydrochloric acid

Scissors

Distilled Water

Measuring Cylinder

Gavin Martin

Results:

Amount Of Hydro-

Amount of Distilled

Time (s)

Rate = 1/time

chloric acid (cm3)

Water (cm3)

10

0

10.41

0.1

9

1

16.38

0.06

8

2

20.33

0.05

7

3

30.19

0.03

6

4

35.32

0.28

5

5

54.76

0.19

4

6

87.93

0.11

3

7

243.76

0.004

2

8

300+

n/a

1

9

300+

n/a

0

10

Infinity

n/a

I then put these results into graphs.

Analysis:

The results for this experiment can be used to very effectively show how the concentration of Hydrochloric acid can be used to affect the speed and rate of a reaction.

The first graph I have drawn (Time – Concentration) shows excellently how much water (concentration) will affect how fast Magnesium will dissolve in Hydrochloric acid. It steadily slows down the speed of the reaction until it seems to break a sort of barrier, where at 7cm3 of water the difference between 6cm3 and 7cm3 is 153 seconds. This graph is positively aligned.

The second graph I have drawn (Rate – Concentration) shows again perfectly how varying the concentration of the acid (weakening) results in the reaction taking longer. One result looked out of place on this graph and so I re-did that one result and found my new result to correlate better with the remainder of the graph.

Gavin Martin

The more acid (concentration) particles in the solution the more likelihood there is of collision with the magnesium.

Magnesium Magnesium

Strip Strip

Less acid, more distilled water More acid, less distilled water

The ore violent reactions took less time and had small amounts of distilled water, created bubbles. What can be told by these bubbles is that the reaction is violent and therefore the molecules are vibrating and moving around quite a lot. This means they hit the magnesium more often and so the magnesium reacts faster. Therefore the magnesium takes lees time to disappear.

Conclusion:

To conclude I believe my experiment to have gone very well. It has shown how the reaction between Magnesium and Hydrochloric acid can be affected very easily by a few changes to the experiment. Concentration alone can make a great affect to all aspects of the experiment. The two graphs I have drawn are both good representations of the results that I concluded from my experiments.

I have forgotten to mention that to keep the Magnesium from floating at getting non-correlating results I weighed it down with a paperclip. This would also cover up some of the Magnesium strip and so would slow the results down by a few seconds or more, as part of the surface area of the Magnesium would not be in contact with the acid.