Why Should A Magnesium Ribbon Be Cleaned Before Burning In Air?

Magnesium is one of the most common element found in the Earth's crust. In its raw form it burns in air, it is due to its property of burning brilliantly and giving out a white light that it is used in fireworks.

Magnesium combines with oxygen in the atmosphere to form magnesium oxide, thus changing the initial identity of Magnesium. A chemical reaction has taken place, this can be determined because there has been a change in colour, may be temperature to some extend and change in its properties.

If we want to burn a magnesium ribbon, (while performing an experiment to prove that magnesium on burning combines with oxygen and magnesium oxide is formed) it has to be cleaned with fine sandpaper or steel wool this will remove all the oxide coating which may have been deposited on the ribbon. The ribbon if coated with oxide, will not facilitate burning easily and one will not get desired results from the experiment.

Thoroughly clean the magnesium ribbon, free it from oxide deposits and thereafter burn, a dazzling bright flame will be seen. A chemical reaction takes place whereby the magnesium combines with the oxygen present in the air and gets converted into magnesium oxide and what remains is a white powder.

To remove the "dirty" oxide layer which slows down the burning reaction. It is a bit like removing the rust (oxide layer) off iron before reacting iron with something.

Most metals, like iron and magnesium, form an oxide with exposure to air, and we call this tarnishing, corrosion, or particularly in the case of iron-based metals - rusting.

Some metals, such as sodium, react so readily with air that we store them under oil or kerosene.

Magnesium ribbon has a layer of magnesium carbonate on it. Which prevent it from burning there fore a magnesium ribbon be cleaned before burning

A magnesium ribbon should be cleaned before burning to remove the oxide deposits present on d ribbon. The ribbon should be cleaned thoroughly cleaned with sandpaper...the oxide deposits are formed due to corrosion.

 magnesium ribbon is cleaned before burning so coating of impurity (such as oxide) formed on its surface is removed and it become pure magnesium

To remove the layer of oxide formed naturally from leaving it exposed