in an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely... In an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely burnt in oxygen.after cooling the product weighted 4.0g. (a)explain why it was necessary to clean the magnesium ribbon? (b)what observation was made in the crucible after burning? (c)why was there an increase in mass? (d)write the equation for reaction which took place in the crucible? (e)the product in the crucible was shaken with water and filtered.​