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)