Magnesium Oxide Lab

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Purpose
In this experiment, the empirical formula of magnesium oxide was determined by converting a sample of magnesium into magnesium oxide and then determining the molar ratio of magnesium to oxygen. This ratio was found by placing a sample of magnesium into a crucible then heating it in the presence of air. To ensure that the reaction was complete the crucibles were fired multiple times and also massed between each firing. This reaction then formed magnesium hydroxide (Mg(OH)2) and magnesium nitride (Mg3N2). Water (H2O) was added to these two products in order to create magnesium oxide. By subtracting the mass of the magnesium sample from the mass of the magnesium oxide the mass of oxygen that formed the oxide was determined. The number
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As seen in the first equation magnesium nitride and water (H2O) react to form magnesium hydroxide (Mg(OH)2) and Ammonia gas. With the addition of heat, the magnesium hydroxide is able to react into magnesium oxide (MgO). Water is also created in this reaction but due to the heat it evaporates.
The contents left inside the crucible should only be magnesium oxide, however if not all of the magnesium reacted during the firing process there would be bits of pure magnesium left in the crucible. The result of this error would show an empirical formula ratio that would be too high in magnesium. If there was unreacted magnesium that would mean that less magnesium oxide was created which in turn would mean that less oxygen had bonded with magnesium. This excess magnesium would alter the experimental molar ratio and the empirical formula.
If the magnesium had not fully reacted the resulting empirical formula may come out as something like Mg2O3. The magnesium in the resulting would have a 3+ charge and the oxygen would have a 2- charge this formula would not follow the typical periodic trends because Mg would normally have a 2+ charge. If done correctly the empirical formula for magnesium oxide would be MgO because Mg has a 2+ charge and O has a 2- charge so s stable compound of magnesium oxide would have a 1:1 ratio of magnesium and
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