Question

why should mg ribbon be cleaned before burning in air

Answer 1

It may contain impurities, which should be removed.

Answer 2

Hi Mate here is your answer,

● Magensium Reacts(Mg) with the Oxygen(02) to form Magesium oxide(MgO).

● But when a magnesium ribbon is left without anything or anywhere, still it is in contact with the Oxygen due to which a layer of magenesium Oxide form over the ribbon.

■ Before burning in air the magnesium Ribbon is cleaned by rubbing with a Sandpaper. This is done to remove the protective layer of magnesium oxide from the surface of magnesium ribbon .

■Because of presence of Mgo on the surface of Magnesium causes hurdle burning or rough burning.

☆Hope it helps you a lot .....☺☺☺♤