Why should magnesium ribbon be cleaned before use?

Question

Why should magnesium ribbon be cleaned before use?

Answer 1

Because it has a coating of oxide, MgO, on it. So, if you are going to make a Grignard reagent, the halide-ether solution has to get at a clean Mg-only surface. This is also the purpose of adding a crystal of iodine to the solution. It forms a minute amount of MgI2, further cleaning the surface to the level of Mg atoms.

Answer 2

To get rid of the oxide or substances which on the surface of the Mg ribbon.

Answer 3

mg is a reactive metal........so it forms a oxide layer......in order to remove that layer we claen it with sand paper

Answer 4

b'coz mg ribbon when exposod to air it vapourises.in order to avoid the loss we prefer to clean it