Making Cars – Revision Packs (C2) Rusting and Corrosion: The word equation for rusting is: Iron + Oxygen + Water Hydrated Iron (III) Oxide REMEMBER – different metals will corrode at different rates. Materials Used in Cars: Only iron and steel can rust; all other metals will corrode. Acid rain and salt water will accelerate the rate of rusting; you see a lot of rusting iron or steel on sea fronts because the salt water from the sea accelerates the rusting. Rusting is an oxidation reaction because iron reacts with oxygen to form an oxide. Aluminium does NOT rust in moist air because it Aluminium is used for the car body because it has a low density, is malleable (can be shaped easily) and does NOT corrode. Some car companies use iron or steel Glass composite / glass with plastic is used for the windscreen because it is transparent (see- through) and
Transcript
Making Cars – Revision Packs (C2)
Rusting and Corrosion:
The word equation for rusting is:
Iron + Oxygen + Water Hydrated Iron (III) Oxide
REMEMBER – different metals will corrode at different rates.
Materials Used in Cars:
Only iron and steel can rust; all other metals will corrode.
Acid rain and salt water will accelerate the rate of rusting; you see a lot of rusting iron or steel on sea fronts because the salt water from the sea accelerates the rusting.
Rusting is an oxidation reaction because iron reacts with oxygen to form an oxide.
Aluminium does NOT rust in moist air because it has a protective layer of aluminium oxide which does NOT flake off the surface like rust does.
Aluminium is used for the car body because it has a low density, is malleable (can be shaped easily) and does NOT corrode. Some car companies use iron or steel because they are malleable and strong.
Glass composite / glass with plastic is used for the windscreen because it is transparent (see-through) and shatterproof (but it may crack).
Making Cars – Revision Packs (C2)
Alloys are mixtures of elements, at least one of which is a metal. They often have more useful properties than the metals they are made from. An example of an alloy is steel which is made of iron and about 1% carbon; it is more useful than iron because:
- It is harder and stronger- It is less likely to corrode/rust than iron
You can build car bodies from aluminium or iron/steel. There are advantages and disadvantages of both:
Metal AdvantagesAluminium It is lighter (low density) so fuel economy is improved.
It doesn’t corrode as quickly; this means the car body will last longer.
Iron/Steel It is very cheap.It is much stronger, and as such less damage is caused in accidents to the car and driver.
Recycling:
Plastic is used in dashboards and dials because it is cheap, rigid and doesn’t corrode.
Fibre is used for car seats because it can be woven into textiles and dyed. It is also hard-wearing.
PVC is used for the copper wire coverings because they are flexible, do not react with water and are electrical insulators.
Copper is used in the electrical wires because it is ductile (can be drawn out into a thin wire) and most importantly, a good electrical conductor.
Lead is used lead-acid batteries because the reaction with lead oxide creates electricity.
Making Cars – Revision Packs (C2)
Many people believe that materials from old cars should be recycled for new cars. There are laws which specify that a certain percentage of materials used to build new cars must have been recycled in an attempt to help protect the environment.
Advantages Disadvantages- Less mining happens, so more
finite resources are preserved- Less crude oil needed to make
new plastics- Less waste means that less
landfills have to be built- Fewer toxic materials, like lead
from car batteries, are dumped
- Fewer mines are built and there are thus less mining jobs
- The process of separating the materials is difficult
- The separating processes may cause pollution
- Some of the recycling processes are extremely pricey
