Question

Describe how you would separate a mixture of water, sand and iron metal filings. Which separation techniques would you use?

Answer 1

Water may be simply filtered off. The iron filings may be dissolved in acid, and this solution filtered from the sand.

Explanation:

`Fe(s) + 2HCl(aq) rarr FeCl_2(aq) + H_2(g)uarr`

Sand, `SiO_2` to a first approximation, is very inert, and only specialty acids (for instance `HF`) would touch it.