# Comparison of the energy content of different food's

Essay by smelly_grubiesHigh School, 10th grade April 2004

Finding The Empirical Formula of Magnesium Oxide

Aim: The aim of this experiment is to burn a known mass of magnesium in air and find the mass of the magnesium oxide produced. Using my results I can then calculate the empirical formula of magnesium oxide.

Results:

Observations

Before starting I notice that the magnesium is very shiny and flexible.

After one minute of heating the Magnesium appears to be going white.

The Magnesium has caught fire and is glowing orange.

The fire has calmed down and a crumbly white substance is being formed.

Fire has all gone and now I am left with the crumbly white oxygenated iron.

Mass of crucible + lid = 34.00 g

Mass of crucible + lid + magnesium before heating = 34.10 g

Mass of crucible + lid + magnesium oxide after heating = 34.20 g

Magnesium

To find the weight of the magnesium on its own we have to take away the weight of the crucible and lid.

Mass of crucible + lid + magnesium before heating = 34.10 g

Mass of crucible + lid = 34.00 g

Therefore, the mass of the magnesium = 0.10 g

Oxygen

We need to do the same to find out the mass of the oxygen o the magnesium.

Mass of crucible + lid + magnesium oxide after heating = 34.20 g

Mass of crucible + lid + magnesium before heating = 34.10 g

Therefore, the mass of the oxygen = 0.10g

We will now need to change the masses into moles:

Magnesium

0.10 / 10 = 0.01 mole

Oxygen

0.10 / 10 = 0.01 mole

Ratio of moles in each element

Mg : O

0.01 : 0.01

1 : 1

Therefore the empirical formula for Magnesium Oxide is MgO

Conclusion: I thought my experiment went very well.