C15 Flashcards
What is corrosion?
Chemical reaction between a metal and the environment which can affect its appearance and strength
Word equation for rust
iron + oxygen + water –> hydrated iron
Scientifc name for rust
Hydrated iron (III) oxide
What type of reaction is rusting?
Oxidation reaction
What 3 ways can be used to prevent rusting?
- Physical barriers
- Galvanisation
- Sacrifical protection
What 3 things can be coated to iron or steel to prevent it rusting?
- Paint
- Oil or grease
- Plastic
Useful properties of copper
- conducts electricity well
- malleable
- conducts heat well
- unreactive
What is an alloy of copper and zinc?
Brass
What are metals reacting with in the environment when they corrode?
- Oxygen
- Water
Examples of metal alloys
- gold
- steel
- aluminium
What are ceramics?
Ceramics are non-metal solids with high melting points that arent made from carbon-based compounds
What type of glass is commonly used in kitchenware and chemical glassware?
Pyrex
2 types of glass ceramics
- soda lime glass
- pyrex
Conditions to produce low density poly(ethene)
- moderate temperatures
- catalyst
- high pressure
Uses of LDPE
- bags
- bottles
How are clay ceramics made?
By shaping a wet clay and then heating in a furnace using a mould
Examples of clay cermaics
- pottery
- bricks
What are composites?
Composites are made of one material embedded in another
Name the raw material that is common to both soda-lime glass and borosillicate glass
Sand (SiO2)
Examples of composites
- wood
- concrete
- fibreglass
What are the 2 materials in composites?
- matrix (binder)
- reinforcement
What is the matrix in concrete?
cement
Uses of HDPE
- water tanks
- drainpipes
What are thermosoftening polymers?
Thermosoftening polymers contain individual polymer chains entwined together with weak forces between these chains.
What type of polymers can be melted and remoulded?
Thermosoftening polymers
What are thermosetting polymers?
Thermosetting polymers contain monomers that can form cross-links between the polymer chains, holding the chains together in a solid structure.
Features of thermosetting polymers
- Hard
- Opaque
- Good electrical and heat resistance
- Brittle
What do plants need nitrogen for?
To make proteins
How do plants absorb nitrogen?
In the form of soluble nitrates from the soil
Conditions used in the Haber Process
- High pressure (200 atm)
- Iron catalyst
- 450 Celsius
Equation for Haber Process
N2 + 3H2 –> 2NH3
Reactants for Haber process
- Nitrogen
- Hydrogen
What is the desired product of the Haber Process?
Ammonia
What 3 elements do NPK fertilisers contain?
- Nitrogen
- Phosophorus
- Potassium
Why are formulated fertilisers better than manure?
- odorless
- increased availability
- not as complex to use
Why is ammonium nitrate so ideal for use in fertilisers?
It contains nitrogen from 2 source
Main sources of soluble potassium
- Potassium chloride
- Potassium sulfate
Phosphate Rock + Sulfuric Acid ——- ?
Single superphosphate
State a source of nitrogen gas that is used in the Haber process
air
Suggest 2 reasons why copper should not be disposed off in landfill sites
- Copper can be reused/recycled
- Copper is expensive
