Empirical Formula For Magnesium Oxide

The Empirical Formula of Magnesium Oxide

Aim.

To find out the empirical formulae for magnesium-oxide

Introduction.

The empirical formula of a compound tells us the types of atoms present in a compound as well as the simplest whole-number ratio of the different types of atoms. The empirical formula does not tell us the actual number of atoms in the molecule.

The mass of Mg + the mass of O2=mass of MgxOx. Knowing the mass of magnesium used and the mass of magnesium oxide produced you can determine the mass of oxygen used. The ratio between number of moles of magnesium used and number of moles of oxygen used can be calculated and the empirical formula can be written on the basis of

Gauze

4. Crucible and Lid

5. Tongs

6. Heatproof mat

7. Safety glasses

8. Magnesium

Diagram.

Method.

1. Place a clean, dry crucible (check for any cracks) with its cover on a clay triangle supported by a tripod. Adjust the flame of a Bunsen burner so that the crucible is just above the hot part of the flame. Heat the crucible strongly for five minutes. The bottom of the crucible should glow red during the heating.

2. Remove the crucible, using the crucible tongs, and place it on the ceramic pad to cool. After the crucible has cooled to room temperature (this will take about ten minutes), weigh it with its cover on an analytical balance to 0.001 g. Record the weight on the data sheet.

3. Weigh out 0.3g of magnesium and place it into the crucible. Weigh the magnesium, crucible and cover on an analytical balance. Record the weight to 0.001 g.

4. At frequent intervals, remove the burner and slightly lift the crucible lid using tongs, quickly replacing the lid so as to lose as little magnesium oxide 'smoke' as possible. Repeat the process patiently until the magnesium ceases to flare up, then remove the

You should not be able to see any shiny metallic surfaces. Allow the crucible to cool then replace the lid and reweigh the whole. Record the mass.

5. Repeat this 5 times so that you will be able to gain an average result.

Fair Test.

To make this a fair test we weighed the empty crucible and lid before adding magnesium. This means that the different weights of the crucibles could be accounted for. This allowing any minor errors in the experiments result to be averaged out. To make this a lot more accurate we carried the test out 5 times.

Before each time we carried out the experiment we cleaned the crucible and lid thoroughly making sure that there was no excess foreign materials of any sort to tamper with the chemical reaction.