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 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 questions1A The chemical symbol for iron is Ir.1B Iron is produced when iron oxide
reacts with carbon.1C The other product formed when
iron oxide is reduced is carbon dioxide.1D Salt is necessary for rusting to
occur.1E Rust is iron sulfide.
F
T
Fe
F
F oxide
T
2A Aluminium is produced at Tiwai Point in Southland.2B Aluminium is used in power wires because it is a good conductor of heat.2C Aluminium can be made by reducing aluminium oxide with carbon.2D Aluminium is a very unreactive metal.
T
F
electricityF
Chemical reductionF
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
Electroplating
Chrome and nickel coating
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)