Why is a magnesium ribbon rubbed with sandpaper before burning it?
Answer and explanation
Correct answer: To remove the magnesium oxide layer from its surface
On exposure to air, magnesium ribbon develops a thin layer of magnesium oxide on its surface. This layer prevents direct contact between the metal and oxygen and hinders burning. Rubbing with sandpaper removes the layer and exposes fresh magnesium for combustion. It does not lower the ribbon’s melting point.
Frequently asked questions
What is the correct answer to this question?
To remove the magnesium oxide layer from its surface
Why is this the correct answer?
On exposure to air, magnesium ribbon develops a thin layer of magnesium oxide on its surface. This layer prevents direct contact between the metal and oxygen and hinders burning. Rubbing with sandpaper removes the layer and exposes fresh magnesium for combustion. It does not lower the ribbon’s melting point.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
