Presentation on theme: "Iron and Aluminium Miss Jan. Iron and aluminium SLOs investigate the reactions of iron and aluminium with oxygen, water, and acids be able to explain."— Presentation transcript:
Iron and aluminium SLOs investigate the reactions of iron and aluminium with oxygen, water, and acids be able to explain the different reactivity of these two metals
Rusting experiment Number 1-7 down the page – record observations
Results Things needed for rusting are: Conditions that speed up rusting are: Conditions that slow down rusting are: Oxygen and water (and of course, iron) Salt, exposure to oxygen Sacrificial metal, dry air
“Iron and Aluminium” sheet Answer the true or false questions 1AThe chemical symbol for iron is Ir. 1BIron is produced when iron oxide reacts with carbon. 1CThe other product formed when iron oxide is reduced is carbon dioxide. 1DSalt is necessary for rusting to occur. 1ERust is iron sulfide. F T Fe F Foxide T
2AAluminium is produced at Tiwai Point in Southland. 2BAluminium is used in power wires because it is a good conductor of heat. 2CAluminium can be made by reducing aluminium oxide with carbon. 2DAluminium is a very unreactive metal. T F electricity F Chemical reduction F
Iron rust is porous – allows oxygen to enter the metal, which allow more rusting
Rusting Aluminium? Aluminum is actually very prone to corrosion. However, aluminum corrosion is aluminum oxide, a very hard material that actually protects the aluminum from further corrosion. Aluminum oxide corrosion also looks a lot more like aluminum, so it isn't as easy to notice as rusted iron.
“How to prevent rusting” sheet Each table group read through and summarize one method of preventing rust. Then report to back to the class – report should contain: What is this method? How does it work?
Sacrificial metal To be bolted onto the hull of the boat Why is it labeled “do not paint”?
Galvanised iron Coat of zinc – prevent water or oxygen from reacting with iron
Questions about rusting 1. Iron oxide 2. Iron, water, oxygen 3. Iron + oxygen iron oxide 4. Brass (Cu + Zn) does not rust. Steel (99% Fe) rusts 5. Painting provides a barrier to water and oxygen, preventing them from reacting with iron
6. Two sacrificial metals: magnesium and zinc 7. Hull of ship or drilling platform, hot water heater 8. 9. Zinc 10. Zinc prevents water or oxygen from reaching iron. Also acts as sacrificial metal (will corrode before iron)