Magnesium Oxide

What I learned from this is that has the mass increases so does the time it takes for the magnesium to burn. This is because more energy is required to burn more magnesium which means more time would be need to provide it. I can also tell that after repeating to see if there was a reaction there was no longer an increase in mass which meant that there were no longer any oxygen atoms joining up with any magnesium atoms.

Main experiment:

List of Apparatus I have used:

• Bunsen Burner
• Crucible and Lid
• Digital Balance – 0.01g
• Goggles
• Heat Proof Mat
• Magnesium Ribbon (200cm)
• Pipe-clay triangle
• Tongs
• Tripod

Safety

We used the crucible and lid because it won’t crack which means there would be no injury to anyone.  If I was to use glass the chanced of and injury would be high. Another advantage for safety with the crucible is that we won’t be able to see the light produced from the creation which means there would be no risk of your eyes being damaged. We used a heat proof mat so that the table will not get burnt or anything else. We would also use goggles because at some point during the experiment we would be lifting the lid to see if the reaction has stopped so using the goggles causes a decrease in glare from the light and it was also used to prevent any particulates from entering my eyes. I also tucked in my tie in my shirt because there was fire from the Bunsen burner and I did not want to get anything easily loose on me to catch fire so tucking my tie in would lower the chances of injury to me. We also checked the heat of the crucible and lid to if it was cool enough to hold by using the harmless method; we hovered our hands over the crucible and lid to see if any heat was radiating to our hands and we could not feel any feat we would light touch the crucible for half a second to get a better sense of the heat and if it feels cool we would then take it back.  

Method

What I’m going to measure is the mass of the magnesium ribbons at different lengths, and I’m also going to measure the amount of magnesium oxide it makes. The mass would be measured by a digital balance (0.01g), which was very accurate way of measuring the mass because it can detect up to two decimal places. To make sure it’s a fair test we took two tests for each length so that we could get an accurate average. We also used a pipe-clay triangle so that the crucible would not experience heat loss (if we were using a gauze) which would affect how much magnesium oxide is produced. We also used the ruler to make sure that the lengths that we used were as accurate as it can be so that the results are fair. How we set up the equipment was that we could have the meat proof mat so that there are no burns around the area or the possibility of fire. The crucible and lid would be placed above the pipe-clay triangle so that the heat would reach the crucible in the right place. The tripod would be used to keep the crucible and lid above the Bunsen burner at the right distance. We would also lift the lid from time to time to see if the reaction has stopped.  We can tell if the reaction has stopped because there would be no bright light. Then we would reheat it to see if the reaction has fully stopped. We can tell if the reaction has fully stopped because there would be no increase in mass.  Next time I would do two experiments at the same time so that I could get my results quicker.

DIAGRAM:

This table shows two results from each length showing the mass of magnesium and the mass of magnesium oxide produced. The two sets of results from each length were then turned to an average so that we can get an accurate figure. I then plotted a graph of these results so that I can see a clear trend. The reason why I took many readings from different lengths is because so that I could get different readings for mass so that I can plot them on the graph at different points so that it can give me a line of best fit. I can’t have only 1 point connecting to zero to make a line of best fit because it would not be a very reliable line.

Analysis

The type of graph I have is as straight line in a positive correlation. The results are directly proportional which means as the mass of magnesium goes up, the mass of magnesium oxide goes up. The ratio is a constant ratio would always stay the same as long as the magnesium ribbon gets a constant supply of the same amount of oxygen every time throughout the whole experiment. This is because there are more magnesium atoms for oxygen to join with. The formula for working out the slope is:
       

        My equation was: 

This shows that the magnesium oxide which I have produces is Mg3O2 because 1.44 (gradient of Mg3O2) is the closest match to my gradient, 1.5. You can’t use anything like half an atom so magnesium would lose 2 electrons and give them to oxygen and because they would become ions the structure of the molecule would be an ionic bond in a giant lattice. I used the points 0.00 because it would be the easiest to deal with. The gradient links directly to the increase in product because it shows a positive correlation continuously.  

Evaluation

The things that prevented or could have prevented our results from being reliable and accurate are these:

• Lifting the Lid from the crucible – How this affected our results is that while lifting the lid some smoke would be released into the air and that smoke is magnesium oxide and because there is magnesium oxide being released into the air that means there would be a reduction in mass which also means that we would get the wrong result for a particular length. Why we had to lift the lid was so that we could check if the reaction stopped and to let oxygen in so that the reaction could continue well. How I could make sure that this does not happen is by tilting the lid enough so that I can see if the reaction has finished and I would only tilt it for a second so that very, very little smoke get released.
• Layer of Magnesium Oxide on the crucible – The effect if this is that it would increase the mass of magnesium oxide we record because there is extra magnesium oxide that was not cleaned off. This would cause our results to be unreliable because it would almost be like we have made a product without anything is apparently (according to scientists) impossible. How I could prevent this from happening is by making sure that I clean the crucible so that any if any magnesium oxide was left in the crucible it would be removed. Or we could just use a new crucible.
• Other formulas for magnesium oxide – There uncountable numbers of possible formulas, so out of all the possible formulas there are there is a low chance that the formula that my data shows it could be may not be it, so this makes my conclusion unreliable. How we could improve our accuracy for this is by taking more records of other formulas and their gradients.
• Unstable balance – This would have an impact on my results accuracy and reliability because the balance kept on changing due to vibration from tables being hit and by wobbling the table which cause the balance to be unstable for quite some time.  Why this is affecting our results is because we cannot be sure if the readings we have recorded are reliable because we recorded them while the balance was unstable. A way in which we could avoid this from having an effect on our results could be by isolating the room during the time we take in the results so that there would be minimal vibrations travelling through the table and floor.
• Distance between the crucible and the flame from the Bunsen burner – How this can alter my results accuracy is by creating less magnesium oxide because if the distance between the two are to long then there would be less heat reaching the crucible but this would only impact our results if the distance between the two was different each time because for each tests the impact of the affect would be the same.

• Cutting magnesium ribbons in right lengths inaccurately – This would affect my reliability by giving me incorrect readings for each mass because when recording the mass I would be recording a result which would be completely of scale if the lengths were cut very accurately. How I could prevent this from happening is by using a ruler, stretching out the ribbon and cutting the ribbon with appropriate and accurate equipment e.g. scissors.
• E=MC2 – This comes into effect in my experiment because before measuring the crucible we needed to wait for the crucible to cool down otherwise the heat would cause an increase in mass. So we would wait for the crucible to cool down before weighing it as energy is mass and mass is energy regardless of form of energy according to the theory behind E=MC2. If I don’t wait for the crucible to cool down then my result would appear that the magnesium oxide as been formed from a higher mass of magnesium.
• Not just oxygen reacting with oxygen – In the atmosphere there is not only oxygen, oxygen is only 21% of the atmosphere, 78% is nitrogen so what would also be made is magnesium nitrate. This would mean that some of my results could be unreliable because I don’t know exactly how much nitrogen oxide has really been made in there is also nitrogen attached to magnesium. What I would do is remove the nitrogen by adding water. This would then create magnesium hydroxide and what I would do to change it to magnesium oxide is by heating it.

I would not say that my results are very reliable because of the formula that I have create was Mg3O2 but logically it should be MgO because the correct ratio would 24:16 in mass terms and in the terms of the number of atoms from each element joining up against each other should be 1:1 and this is only because magnesium would lose 2 electrons to get a full shell and the oxygen would gain 2 electrons to get a full shell to make an ionic bond in a giant lattice. Another reason why I would say that my results are quite unreliable is because there were a lot of problems which caused the test to be quite unfair which was the lack of oxygen so what we did was we lifted the lid several times to get some oxygen in, but by doing that it lets some magnesium oxide out which would cause an accidental decrease in mass. But when looking at my graph and ignoring the gradient being 1.5 all my points on the graph are either or very close to the line of best fit and the average points don’t scatter and the error bars are mainly small which indicates that my results are accurate, they’re just not very reliable because I did not get the formula MgO. I am confident that my results are accurate but I’m not confident enough to believe that my results are reliable because when looking at the logical ratio it should be 24:16 but mine is 72:32 in atomic mass terms. Which does not really make much sense because naturally an atom would want a full shell but in this case only 4 out 5 atoms in the molecule are getting full shells, so I would believe that my results are very unreliable and when looking at what possible formulas there are, there really are loads which means that the formula which I have is very unlikely to be true, in fact many different formulas could have been made during just one test for one length. The method which I have used was quite accurate because of the equipment which we have used. One very accurate equipment which I used was the digital balance (0.01g) and that was very accurate because it was able to measure the small changes in mass. The Bunsen burner was also good to use because it gave a constant supply of heat at roughly the same temperature throughout the experiment.

The pipe-clay triangle made your results accurate because it made sure that the crucible was placed securely on the tripod and it also made sure no heat was blocked for the crucible. A method such as waiting for there to be no change in mass was an accurate method because it was easy to see if there was no change in mass. Overall, my whole experiment is not very reliable my results are very accurate, according to my graph.