Testing magnesium as a bicycle frame material

 

Name: Sayo

Partners : Hana C

Date: 12/4/2015 & 12/7/2015

Aim:

1. To know how the molarity of an acid affects the time for magnesium to react.

2. To determine which acid, hydrochloric or sulfuric acid react magnesium faster.

Hypothesis: I think that magnesium will react faster when the molarity of acid is higher. This is because the higher the molarity of acid, the rate of magnesium to react is faster (longman). To have a reaction, there has to have a collision. When the molarity is higher, there are more particles in the acid. When there are more particles, the number of collision between the acid and magnesium increase. Also when there are more collision, the rate of magnesium to react increases. On account of this, when the molarity of acid is higher the speed of reaction will increase.

Variables: 

Independent Variable

(What you decide to change.

How will you change it?)

Dependent Variable 

(What you measure.

How will you measure?)

Controls

(What will you keep the same to make it fair?

What steps will you take to control the variable?)

concentration of acid

(sulfuric and hydrochloric acid):

-Molarity of Acid

I will change it by changing the molarity rate of acid. I decided to change the amount of acid and instead I put in the H2O. In total I made sure all the liquid adds up to 10ml.

There will be four different molarity of acid. 1m, 7.5m, 0.5m, 0.25m.

time taken for magnesium strip to dissolve:

-I will measure the time it took magnesium to react.

I will measure it by putting the acid (each sulfuric & hydrochloric) and water (H2O) in the test tube. In each test tube I will put each amount (half a cm) of magnesium. To make sure of my result, I will do two trials.

  • Amount of H2O/Acid

Each try I will make sure all the test tube add 10 ml of liquid in total.

  •  Size of magnesium

(half a cm) I will make sure in each trial, measure the cm of magnesium.

  •  Time (Stopwatch)

I will make sure to make the time accurate in each trial, to make sure all the result will be accurate.

Materials:

Diagram:

 

Methods:

Sulfuric Acid and Hydrochloric Acid

  1. Collect all materials and rinse, dry them to make sure they are not dominated.
  2. Then take all your materials (listed above) and place on table.
  3. Make sure there is nothing on the table, except the materials.
  4. First label the beaker to know which one is the sulfuric acid and water. One of the beaker should be labeled sulfuric acid and on another one, it should be labeled water (H2O). (For my experiment I made a mark with the white board marker. Sulfuric acid=red. Water = blue)
  5. In the beaker that has a label sulfuric acid, put about 60 ml of sulfuric acid (we are going to use 50 ml total for the experiment). And in another beaker put about 60 ml of distillated water.
  6. Then put 8 test tube on the test tube rack and label each test tube. 2 test tube should be labeled 1m, 2 test tube should be labeled 0.5m, 2 test tube should be labeled 0.75, and last 2 test tube should be labeled 0.25m.
  7. From the beaker that has the sulfuric acid, using the dropper measure 10 ml of sulfuric acid using the measuring cylinder.
  8. Put that measured acid in the test tube that has the label 1m. Repeat the same process other times.
  9. After step 8, measure 7.5ml of sulfuric acid with measuring cylinder and put it in the test tube that says 7.5m. This time you will need to measure the distillated water too. For 7.5m you will need measure 2.5ml of distillated water.

*All of the liquid should be measured by using the dropper and measuring cylinder.

  1. Repeat this for all the test tube. For 0.5m measure 5 ml of acid and water, for 0.25 measure 2.5ml of acid and measure 7.5ml of water.
  2. After you have done this, for each of the 2 test tube, make sure all the liquid are mixed together. To mix it, just move the test tube back and forward. Be careful not to touch the liquid.
  3. Using the ruler and the scissors, cut the magnesium. Each strap of magnesium should be about half a cm.
  4. In each test tube, put one strap of magnesium. When you put the magnesium in the test tube, at the sametime, start the stopwatch.
  5. In all the test tube the magnesium should start to bubble. (*If you use the stopwatch on the iPad it will be good because it can time it by lap time and you can measure the time at once. But normal stopwatch is good enough.)
  6. If the magnesium had ended reacting (dissolved), stop the stopwatch. Put all the result in the spreadsheet and see the average time it took magnesium react in acid.

        Safety

  1. Make sure all bags are under the table when you do the experiment.
  2. When you do the experiment, make sure there is nothing on the table except for the equipment.
  3. We are going to use acid in this experiment. Make sure you put on a safety glasses to protect your eyes.
  4. If you got any acid on your skin make sure to rinse it off with a water.
  5. You will have to handle the acid carefully, as it is extremely corrosive.

        Control (H2O)

  1. To make sure all magnesium was not reacting to water, you will do the ‘control’ trial. This trial is where we put 10 ml of water in the test tube. Of course you will put half a cm of magnesium.
  2. For this one you don’t need to time it. Just put half a cm of magnesium in the test tube, and see if the magnesium reacts. This trial should not react that much, this is just to make sure if all the experiment was a fair test.

        Record your Data/Calculation

  1. Experiment should have the result recorded.
  2. First, make a graph like this. This graph is for sulfuric acid. Make another one and change the part that says ‘Sulfuric Acid (molar)’ to ‘Hydrochloric acid (molar).

Time it took magnesium react in sulfuric acid

Acid type

Trials (seconds) +/-1 second

Sulfuric Acid (molar)

Trial 1 (min)

Trial 2 (min)

Average (min)

Example. 1m

0.39

0.49

0.44

  1. In each trial make sure to record the molarity of acid, the time it took magnesium to react.
  2. When two trials of time are recorded, you will need to calculate the average.
  3. To calculate the average you will need to add two trial. For example on the graph it says, 0.39 and 0.49. Add 0.39+0.49=0.88, then divide it by 2. That will give you the average, for this it is 0.44.
  4. Record all the trial on the table, make a graph. Graph should be a line graph. This is an example.

Results:

Time it took magnesium react in sulfuric acid

Acid type

Trials (seconds) +/-1 second

Sulfuric Acid (molar)

Trial 1 (min)

Trial 2 (min)

Average (min)

1m

0.39

0.46

0.44

0.75

1.02

1.11

1.07

0.5m

2.05

2.05

2.05

0.25m

10.45

11.2

10.83

Time it took magnesium react in hydrochloric acid

Acid type

Trials (seconds) +/-1 second

Hydrochloric Acid (molar)

Trial 1 (min)

Trial 2 (min)

Average (min)

1m

0.39

1.18

0.785

0.75

2

2.15

2.08

0.5m

7.05

7.28

7.165

0.25m

27.5

33.3

30.4

To calculate the average you will need to add two of the trials. For example, the first trial for sulfuric acid (1 molar), on the table it says 0.39 and for second trial it says 0.49. Add these two number (0.39+0.49) and it should add up to 0.88, then divide it by 2. That will give you the average. For this example it would be 0.44.

Average=trial 1+trial 2 / (divide) by 2 (number of trials)

Control (H2O)

Trial 1

10ml

No reaction (NA)

Observation (For both acid)

When the magnesium were put in the solution, it started to bubble. Also, when I tested with higher molarity the speed of bubble that came out from magnesium were really fast and also there were more bubble. For 0.75 and 0.5 speed that magnesium reacted was quite fast, but 0.25 reacted slower than I thought.

When I put the magnesium in the control test tube (water), there weren’t much bubble (This means speed of magnesium react is not really affected by the water). Another observation was that some of the magnesium pieces kept on going up and down, and most of the time when the magnesium went up, it was the time when the magnesium ended reacting. However, this only happened to some of the test tube, and because of this, sometimes it was hard to see the strip of the magnesium.

Conclusion:

In conclusion, the higher the concentration of acid, the faster the reaction takes place. The two different acid sulfuric acid and hydrochloric acid, had a same kind of result until the hydrochloric was 1 moler. However, as the molarity of acid decreased the time it took magnesium react got slower. At last, magnesium reacted faster when the acid was sulfuric acid. Both acid didn’t have much difference but, as the amount of H2O increased the time got slower and slower. The average time it took magnesium react in sulfuric acid with 1 molar was 0.44min. And the average time it took magnesium react in hydrochloric acid with 1 molar was 0.98min. This result tells that sulfuric acid has more molarity that can make magnesium react faster. Also if you look at the result of 0.25 molar for both acid, you can see that hydrochloric acid took 28.1min more than sulfuric acid to make magnesium react.This is means the time it took magnesium react in two different acid had a big difference. I am certain of my result because, all of times was very close in each trials. Also, the time was close enough to average that shows it is very consistent. However, I only had did two trials which might have not been enough.

I am certain that when the molarity is higher, it takes less time magnesium to react. When the molarity is higher, there are more acid particle to collide with the magnesium. This causes reaction to happen faster. Lastly, I don’t recommend using magnesium to make a bicycle frame. This is because if you look at the result, 0.25m and 1m for sulfuric acid 0.25m took 16.05min to react and 1m took 0.62min to react. Because sulfuric acid is part of an acid rain, if 0.25m represent normal rain, and 1m represent acid rain, in normal rain, magnesium will react slowly, but acid rain will react quickly. And this tells that if bicycle frame that was made by magnesium went outside in acid rain, probably that bicycle will react and it will cause a damage. accordingly, it won’t be a good idea to use magnesium for frame.

Evaluation: 

Issue/problem with the method

How to improve them/what you would do in future

Why the change would make the experiment better

One issue was that maybe the liquid measured by the measuring cylinder was not really accurate which might of caused to not make the result fair.

In future to improve this problem, I should check if all the mm of liquid is equal and has the amount we need. Also even if there are 1 ml in the measuring cylinder, I would make sure to put it back in the beaker with a dropper.

The change would make the experiment better because the result will be fair and accurate. Also the result might be different than what we have got with this experiment.

Another issue was that the timing we put the magnesium in the test tube was different. Because sometimes, the magnesium got stuck on the side of the test tube, I had to push it in and this might have affected the time.

In future I would make sure to put the magnesium in the testube carefully and accurately. If I do it carefully and accurately,  I would be able to be accurate with the time (time to start the stopwatch).

The change would make the experiment better because the time measured will be accurate which make the result more accurate. Also again, the result might be different than what we have got with this experiment.

The strip could have also been of different size, which again

would have made the results not accurate. If the strip had a different cm, the time magnesium to react would be more slower.

Next time, I will make sure all the magnesium had exactly the same size.

This change would make the experiment better because, if the time is accurate the result will be reliable.

Extensions:

One way to find more about this experiment is to use another type of acid. This could be a nitric acid, because it is part of a acid rain and this can also be similar to sulfuric acid. Even Though both of them are part of acid rain, like the time difference between sulfuric and hydrochloric acid, there might be a big difference of time between nitric and sulfuric acid. Also if the magnesium reacted really quickly in nitric acid, it will support the idea of not to use magnesium for bicycle frame. Also another way to find out more, could be to increase the range of molarity using the same experiment what we have just done. Because we did this experiment saying the maximum molar was 1, we can increase it moler to such as 2m or 3m. By seeing these result could also be something good to know more about why using magnesium as a bicycle frame will be not good.

Sources Cited: 

-"Investigating the Rate of Reaction Between Magnesium Ribbon and Hydrochloric Acid."123HelpMe.com. 10 Dec 2015

    <http://www.123HelpMe.com/view.asp?id=148001>.(Same) -"Investigating the Rate of Reaction Between Magnesium Ribbon and Hydrochloric Acid :: Papers." Investigating the Rate of Reaction Between Magnesium Ribbon and Hydrochloric Acid :: Papers. 123HelpMe.com, n.d. Web. 10 Dec. 2015.

-"Rate of Reaction between Magnesium and Hydrochloric Acid Using Vernier Pressure Sensor." SlideShare. Lawrence Kok, 21 Mar. 2011. Web. 10 Dec. 2015.

-"Sign in - Google Accounts." Sign in - Google Accounts. Logman, -. Web. 10 Dec. 2015.