Topic 5: Seperate Chemistry 1 Flashcards
What are the transition metals?
Metals in the centre of the periodic table
What are the typical properties of transition metals?
High melting points
High densities
Transition metals and their compounds are good catalysts
Their ions from colourful compounds
What is an alloy?
A mixture of a metal and at least one other element
What is the link between pure metals and malleability? Why
Pure metals are malleable - layers slide over eachother
What is the link between alloys and malleability? Why?
Alloys are stronger than pure metals - not malleable as new elements distort layers of metal atoms so can’t slide past eachother
What are the uses of copper? Why?
Malleable & Corrosion resistance - used in water pipes
Good electrical conductor - used in wiring
What is brass?
The alloy containing copper and zinc
What are the uses of brass?
Shiny and strong - used for decorative taps and door fittings
What are the uses of gold? Why?
Good electrical conductors and corrosion resistant - used in electronic components
Shiny and malleable - used in jewellery
What are the uses of gold alloys?
Jewellery - the gold is strengthened with other metals like zinc, copper or silver
What is steel?
Alloy containing iron and carbon
What are the uses of steel? Why?
Stronger and less likely to rust than iron - used to make long lasting things like bridges and saucepans
What are the uses of aluminium? Why?
Light and soft - used in drinks cans
Good conductor of electricity - used in overhead cables
What is magnalium?
Alloy containing aluminium and around 5% of magnesium
What are the uses of magnalium?
Stronger, lighter and more corrosion resistant than aluminium - used in cars and aeroplanes
What is corrosion?
Damage to metals when they’re oxidised by oxygen and water from their environment
What is rusting?
Corrosion of iron by water and oxygen (from the air)
What happens if a nail is where there is no air but there’s water?
No rust
MUST USE BOILED WATER
POUR OIL ON TOP TO STOP AIR
What happens if a nail is where there is air but there’s no water?
No rust
USE CALCIUM CHLORIDE TO ABSORB WATER
What happens if a nail is where there is air and there’s water?
Rusts
What are the three ways to prevent rusting?
- Barrier methods
- Sacrificial protection
- Galvanisation
What is the barrier method of preventing rusting?
Coating iron to keep out water and oxygen using oil, grease etc.
What is the sacrificial protection method of preventing rusting?
Attaching a more reactive metal which corrodes first to a less reactive metal
What is the galvanisation method of preventing rusting?
Iron is coated with a layer of a more reactive metal like zinc
What is electroplating?
Coating the surface of a metal with another metal using electrolysis
What is the anode in electroplating?
The metal used for electroplating