Titanium & Aluminium

L.OGive reasons for the uses of aluminium, titanium, and their alloys (D)

Explain why the metals are expensive to extract (C)

Explain the benefits of recycling metals (A)

StarterFor each complete the word equation & then do

symbol equations:- 1. Iron Nitrate + Zinc 2. Lead Sulphate + Iron3. Silver Nitrate + Copper4. Calcium Sulphate + Magnesium

Quest:- What type of reactions are these an example of?

Aluminium• Aluminium alloy has a LOW density –

therefore better than steel for wheels• Has a thin layer of aluminium oxide on it’s

surface stopping H2O + O2 molecules corroding the Al atoms

• Pure Al = too soft. Alloy of 93% Al mixed with Si + Fe

Uses of Al

• As the Si & Fe atoms disrupt the regular pattern of Al they slide over each other less easily = stronger, but still light.

Titanium

• Aluminium and titanium exist in the earth as minerals

• Aluminium usually comes from aluminium oxide in the bauxite ore

• Most titanium exists normally as titanium oxide

Extraction

There are limited amounts of the ores of both metals….. So they’re expensive

Not easy to extract because you can’t heat them with Carbon (Al is higher in the reactivity series)

Its atoms are joined very strongly to oxygen atoms

• If you heat titanium oxide with carbon you make titanium carbide but it makes it brittle

• Al is extracted by electrolysis – this is expensive

• Titanium is extracted by a multi-step process – this is expensive as so much energy is needed

Reduce, reuse, recycle

Recycling Al uses only 10% of the energy needed to make cans from bauxite. Creates less pollution

Practical

• AC1.12.1 The density of aluminium and other metals

Aluminium is used to make a huge variety of items, from car wheels to aeroplanes, from cooking foil to drinks cans. But why? This investigation gives you the chance to begin to find out.

Al Ti Pb Cu Fe

Density (g/cm3) 2.7 4.54 11.3 8.92 7.86

Electrical conductivity, (10–8 siemens/m)

0.382 0.024 0.046 0.593 0.10

Tensile strength (MPa) Between 50 and 110

230 15 Between 220 and 430

210

•Use the data to suggest why aluminium and titanium are used to make aeroplanes.•Which would be the better material for overhead electricity cables – aluminium or titanium? Give reasons for your choice.•Explain why lead is not used for overhead electricity cables.•Explain why an aluminium car uses less fuel than an otherwise identical steel car over the same journey.

Out of 5

Give reasons for the uses of aluminium, titanium, and their alloys (D)

Explain why the metals are expensive to extract (C)

Explain the benefits of recycling metals (A)