Alloyed forms of magnesium have considerable tensile strength. The metal is used when lightness is an essential factor: alloyed with aluminium or copper, it is used extensively in making castings for airplane parts; in artificial limbs, vacuum cleaners, and optical instruments; and in such products as skis, wheelbarrows, lawn mowers, and outdoor furniture. The unalloyed metal is used in photographic flash powders, incendiary bombs, and signal flares; as a deoxidiser in the casting of metals; and as a getter, a substance that achieves final evacuation in vacuum tubes.
The estimated world production of magnesium in 1989 was 350,000 metric tons. The estimated United States production in the same year was 148,000 metric tons.
Bibliography
I gathered this information from: Microsoft Encarta ’95 and The Dorling Kindersley.
Factors
I can investigate these factors:
- Temperature
- Concentration of Hydrochloric Acid
- Amount of Hydrochloric Acid
- Surface Area Of Magnesium
- Catalyst
Here is some more detailed information about the factors:
Temperature will affect the experiment because it can change the rate of reaction. This is because the more energy the particles have the more quickly they move around which means more particle collisions that are more successful (they get the energy from the temperature). Also, when particles collide, they are more likely to react, rather then just bounce off each other, if they are moving faster.
Concentration of Hydrochloric Acid could affect the rate of reaction because the higher the concentration of the acid then the more acid particles per 100cm3 so more collisions per second and then there will be more successful collisions per second.
Amount of Hydrochloric Acid will affect the experiment because by adding more Hydrochloric Acid, there will be more reactant particles with energy to collide successfully.
Surface Area will affect the experiment because when the solid that contains the reactants will be break up into smaller pieces, this increases the surface area. The larger the surface area, the more likely it is that the particles will collide because there is more area to work with.
Catalyst affects the experiment because the catalyst is giving the reactant particles a surface to stick to where they bump into each other. This will increase the number of collisions because the particles have a place to bump into each other.
The factor I have chosen is Surface Area.
Prediction
My prediction is that the more I increase the surface area of the magnesium, the greater the rate of reaction. This is because the larger the surface area, the more likely it is that the particles will collide because there is more area to work with.
Safety
To make my experiment safe we will be wearing goggles, using a pipette for the Hydrochloric Acid and keeping the magnesium that we haven’t used away from the Hydrochloric Acid so it doesn’t become contaminated.
Fairness
I will make my experiment fair by making sure that there is no air in the cylinder that contains the water and by using the same amount of Hydrochloric Acid all the time. I will make sure that there is no Hydrochloric Acid in the test tube because it would change my results. We will only be changing the surface area, so the amount of Hydrochloric Acid (1.5cm³), concentration of HCl (2) and the catalyst that we are using in this experiment will all stay the same.
Apparatus
The apparatus that I will use are a test tube, cylinder, tray, pipette, delivery tube, test tube rack, beaker and scissors.
Rough Method
First I will set up all my equipment. Once I have done that I will then pour some water in the tray that I will have. I will then get three strips of magnesium. Each strip of magnesium will have a length of two centimetres. Then I will cut the magnesium strip into 2 pieces, then 4 pieces, then 8 pieces and 16 pieces. I will then collect the Hydrochloric acid. The amount of Hydrochloric Acid I am going to use is 1.5 centimetres cubed. After that I will fill the measuring cylinder with water from a beaker and make sure that there is not any oxygen in there. Once full to the top I will then put my hand over the cylinder, turn it upside down and carefully put it in the tray without letting my hand slip meaning no oxygen will be escape the cylinder. I will place the delivery tube into the cylinder from the bottom; yet again making sure no oxygen escapes. Now I will put the piece of magnesium into the tube. When it is in the tube I will shut it with the cork connected to the delivery tube, and wait till the gas is produced.
Empty Results Table
Real Experiment
Conclusion
I have found out that by doing this experiment that when we increase the surface area, there is more gas produced. This can be shown in my graph. If I had more time I would like to have done a preliminary study. (If I did my experiment again I would probably have got more accurate results because I would have made less errors that I have now.)
Evaluation
From my results I have found that the larger the surface area of the magnesium, the more gas that was produced. I have succeeded in what I planned to do, which was to find out how the surface area of Magnesium affects the rate of reaction. The results I got were what I had predicted and I did not get any spontaneous results. So I can safely say that my prediction was definitely correct and that the rate of reaction increased as the surface area of magnesium increased because the larger the surface area, the more likely it is that the particles will collide because there is more area to work with.