4Hard6 marks
Iron nails rust slowly in the presence of water and air. When an iron nail rusts, insoluble solid hydrated iron(III) oxide forms. The solid hydrated iron(III) oxide falls off the iron nail.
The rusting of iron nails is slowed down by coating the nails with oil or paint.
Plan an investigation to show which of the two coatings, oil or paint, slows down rusting the most. Your plan must include how the results will show which coating slows down rusting the most.
You are provided with iron nails, oil, paint, water and common laboratory apparatus.
Plan