Question

why should a magnesium ribbon be cleaned before burning in air???​

Answer 1

Answer:

magnesium ribbon reacts with carbon dioxide present in the air to form a protective and inert layer of magnesium carbonate. This layer is unreactive and hence, needs to be cleaned with sand paper before burning in air.

Answer 2

Magnesium ribbon should be cleaned before burning in air because Magnesium metal reacts with the atmospheric oxygen and forms Magnesium Oxide (MgO) layer which is a very stable compound. In order to prevent further reactions with Oxygen, it is therefore necessary to clean the ribbon by to remove the layer of MgO.

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