Ib Chemistry Ia - Oxidizing Magnesium

Only available on StudyMode
  • Download(s) : 206
  • Published : October 23, 2012
Open Document
Text Preview
Oxidizing Magnesium

AIM: To determine the empirical formula of MgO
Mass of Mg/g| Mass of O2/g| Mass of MgO/g|
0.12| 0.07| 0.19|
0.15| 0.08| 0.23|
0.16| 0.08| 0.24|
0.19| 0.11| 0.30|
0.21| 0.11| 0.32|
0.23| 0.09| 0.32|

When a mass of magnesium is burnt in air, it combines with the oxygen molecules to form magnesium oxide. The graph doesn’t completely verify the empirical formula of magnesium oxide. There is a slight difference in the literature value of the empirical formula, MgO and the formula obtained from the graph. There are two points on the graph which do not fit into the trend line at all indicating an error during the procedure of the experiment. The gradient of the graph is 1.3. The uncertainty calculated from the steepest and least steep lines is

In the graph, there are two points that lie away from the trend line. This might have happened due to human error or a limitation in the experiment. One of the limitations was that the experiment required us to lift the lid of the crucible from time to time to check and see if the reaction was finished. When this was done, it was observed that some white smoke escaped. This was the product, Magnesium Oxide. Any escape of the product would bring about a different set of results. Another limitation was that the crucible was weighed while it was still warm, which caused the product, magnesium oxide to weigh more. Also, the ceramic crucible might have reacted with the magnesium ribbon when exposed to such high amounts of energy. Another drawback was that the magnesium was burnt in air and not in proper oxygen. The magnesium might have reacted with other gases in the air, like nitrogen to magnesium nitride. In the allotted time, there were six different values taken. The time given was sufficient to carry out the whole experiment properly LIMITATION:

The magnesium could be completely cleaned with sand paper to remove...
tracking img