Question

Before subjecting Mg ribbons to flame, it is rubbed with sandpaper. Why?

(a) To increase surface area for combustion

(b) To increase roughness of surface

(c) To remove oxide layer

(d) To remove moisture

This question was posed to me in exam.

Question is from P-Block Elements in section P-Block Elements of Chemistry – Class 12

Answer 1

Correct option is (c) To remove oxide layer

The explanation is: In order to ensure effective burning of the magnesium ribbon, it is cleaned with sandpaper to remove dust particles along with the layer of magnesium oxide, which may prevent it from burning completely.