Magnesium Oxide Formula

Synthesis of Magnesium Oxide and Determination of its Empirical Formula

Background

When elements react to form compounds they do so in specific ratios. The formula that describes the smallest whole number ratio for elements in a compound is the empirical formula. In this experiment, you will heat magnesium in air (a source of oxygen) to generate magnesium oxide. By analyzing the mass of the magnesium and oxygen that have reacted, you will determine the number of moles of each present in the magnesium oxide product.

In the formula for magnesium oxide, the x and y represent the smallest whole number ratio of atoms of magnesium to atoms of oxygen in the compound, magnesium oxide. This reaction is classified as an oxidation-reduction reaction,

However, if both the numerator and denominator are multiplied by 2, the ratio is within experimental error of three moles oxygen per two moles aluminium:

Therefore, the empirical formula of aluminium oxide is Al2O3.

In the experiment, you will conduct a similar experiment and calculations starting with magnesium metal. A known mass of magnesium will be heated in air and will combine with oxygen. The mass of magnesium oxide will be measured; the increase in mass will be oxygen. The calculations will be similar to those shown above.

Safety & Waste

In this experiment, you will be working with a Bunsen burner. The hazards involved with this device involve burns, either of people or objects that are not intended to be burned. When working with a Bunsen burner you should ensure no loose clothing and have your hair tied back.

Magnesium metal is flammable. It burns with an intense white flame that is difficult to extinguish. Keep loose magnesium away from Bunsen burners until it is in a covered crucible. Sometimes the magnesium ignites in the course of the experiment. If it does, avoid looking at it as it could damage your eyes and let it burn itself out. You can then proceed with the experiment; the ignition will not alter your

I expected the ratio of magnesium to oxygen to be smaller, around one to four. Based on the experiment, I concluded that the empirical formula of the compound was Mg11O.

Evaluation

The experiment certainly provided us with crucial information regarding the ratio of magnesium to oxygen, however the results might have been impacted by the environment. Since, the experiment consists of three types variables: controlled, independent and dependent, we are able to manipulate them in order to obtain the most accurate and precise results possible. One factor that had an impact on the accuracy of the experiment was the number of trials. To increase the accuracy we could repeat the experiment minimum 3 times. Another factor that affected the results was the dirty crucible in which were remains of an unknown substance from a previous experiment. It could have impacted the measurements of weight prior to and after the reaction. Moreover, the air that we used in order to obtain oxygen, consists of a combination of different gases, including nitrogen and carbon dioxide. Consequently, to investigate the pure effect of oxygen, we would have to limit the amount of other gases in the