Question

1.Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:
2 mcq
Remove the layer of magnesium carbonate from the ribbon surface
Remove the layer of magnesium oxide from the ribbon surface
Make the ribbon surface shinier
Remove the moisture from the ribbon surface​

Answer 1

To remove the layer of magnesium oxide from the ribbon surface because magnesium oxide hinders the process of burning

Answer 2

Before burning in the air, the magnesium ribbon is cleaned by rubbing with sandpaper to: Remove the layer of magnesium oxide from the ribbon surface. This is because-

• Magnesium is a highly reactive element and hence, it reacts with the oxygen present in the air and forms a coating of magnesium oxide.
• Thus, to remove the layer of oxide of magnesium, the magnesium ribbon is cleaned before the experiment.
• If we don't rub the magnesium ribbon with sandpaper then it will not burn. This will hamper our experiment of the burning of magnesium ribbon in the air and also, will not give desired results.