Starter – in the back of your book Where is Fe on the Periodic table? Where does it fit in the reactivity series? How would you extract it from its ore?
Objectives To be able to list the properties of iron and how these relate to its use. To be able to explain the chemical reaction of rusting in scientific terms; To know how methods of rust prevention works.
Did you know? Fe is the most widely used metallic element The melting point is 1808K and Boiling Point is 3023K Iron ore can contain sand and rock as impurities It was the Chinese in the third century BC who realised that the addition of C to Fe, reduced the melting point
Iron Properties List the physical properties of Fe. List the Chemical properties of Fe.
Iron Properties Conducts heat and electricity Sonorous Ductile and malleable Lustrous High melting point and boiling point Reacts slowly with air when heated Reacts reversibly with steam Reacts well with dilute acids Will displace Zn, Al, Mg, Ca, Na and K out of solution Catalyst Physical PropertiesChemical Properties
You try: For each property think of a use for Fe.
Uses of Fe Conductor – Crocodile clips Malleable – Paper clips Lustrous – Bins High Melting and Boiling Points – Drill bits Catalyst – Haber Process, to make ammonia
Iron has problems Fe is quite brittle, in comparison to other metals and rusts, so often alloys are used. You try: What is an alloy? Name an alloy of Iron.
Rust 1. What is Rust? Hydrated Fe 2 O 3 2. What do you need for rust to happen? Water and oxygen 3. How can rust be prevented? Painting, grease/oil, galvanising, sacrificial protection and alloying.
Task: In your exercise book, detail what rust is, and how it can be prevented.
Classic Rusting Experiment Consider 4 nails in test-tubes with: 1. H 2 O open to the air; 2. in boiled H 2 O, then with a layer of oil on the surface; 3. CaCl 2 and sealed with a bung; 4. in NaCl (aq) open to the air. You try: predict what would happen to each nail after a week, and why you think this.