C2d Flashcards Preview

Chemistry > C2d > Flashcards

Flashcards in C2d Deck (9)
Loading flashcards...
1
Q

What are alloys and why are they useful?

A
  • mixture of two or more metals
  • mixture of metal and a non-metal
  • often have properties that are different from the metals they are made of
  • new properties may make the alloy more useful than the pure metal
2
Q

Name some alloys and there properties?

A
  • steel:
  • iron and carbon
  • harder and stronger than iron (if carbon not higher than 1%), steel corrodes less quickly
  • uses: bridges, ships and cutlery
  • brass:
  • copper and zinc
  • mixture of copper and zincs properties, harder than either of them
  • uses:instruments and doorknobs
  • bronze:
  • copper and tin
  • harder and stronger than tin, more resistant to corrosion than tin or copper
  • uses:springs, bells
  • solder:
  • lead and tin
  • indefinite boiling point unlike pure materials, gradually solidifies as cools
  • uses:solder things together
  • amalgam:
  • alloy containing mercury
  • tooth fillings
3
Q

What is nitinol what are its properties?

A
  • nickle and titanium
  • smart alloy as it has shape memory
  • remembering its original shape and goes back to it even when bent
  • uses: nitinol glasses frames
4
Q

Why do iron and steel corrode easier than aluminium for cars?

A
  • aluminium doesn’t corrode when wet
  • what happens it, aluminium reacts very quickly with oxygen to form aluminium oxide
  • this acts as a protective layer, sticking firmly to the aluminium below and stops any further reaction taking place
  • oxide not crumbly and flaky like rust, so no falling off
5
Q

What is the disadvantage of aluminium over steel for cars?

A

-expensive

6
Q

What are the advantages of aluminium over steel?

A
  • low density so cars will be lighter, giving aluminium cars better fuel economy which saves fuel resources
  • corrodes less, so longer lifetime
7
Q

Why is recycling cars important?

A

-saving natural resources, save money and reduce landfill

8
Q

What materials do you need to build a car and why?

A
  • steel: strong and can be hammered into sheets and welded together (good for bodywork)
  • aluminium: strong and low density (parts of engine)
  • glass: transparent (windows and windscreens)
  • plastic: light and hard-wearing (internal covering for doors) electric insulators (covering electric wires)
  • fibres (natural and synthetic): hard-wearing (cover seats and floors
9
Q

What parts are cars are recycled?

A
  • a lot of metal from cars is recycled
  • most other materials, e.g. plastics and rubber, go to landfill
  • laws placed in Europe to recycle 85% of materials used in a car (95% by 2015)