Why is a magnesium ribbon cleaned by rubbing it with sandpaper before burning?
Answer and explanation
Correct answer: To remove the magnesium oxide layer formed on the surface
Magnesium reacts slowly with oxygen in air to form a thin magnesium oxide layer on its surface. This coating reduces direct contact between magnesium and oxygen. Rubbing with sandpaper removes the coating, so magnesium burns more readily with a dazzling white flame. The rubbing does not change magnesium’s melting point or remove oxygen from the air.
Frequently asked questions
What is the correct answer to this question?
To remove the magnesium oxide layer formed on the surface
Why is this the correct answer?
Magnesium reacts slowly with oxygen in air to form a thin magnesium oxide layer on its surface. This coating reduces direct contact between magnesium and oxygen. Rubbing with sandpaper removes the coating, so magnesium burns more readily with a dazzling white flame. The rubbing does not change magnesium’s melting point or remove oxygen from the air.
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.
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