Metals - SC7 Flashcards
What is oxidisation in terms of loss/gain of electrons and oxygen
Gain oxygen, lose electrons
What is reduction in terms of loss/gain of electrons and oxygen
Loss of oxygen, gain of electrons
What reaction causes corrosion - what is oxidised?
metal + oxygen (metal is oxidised)
What reaction causes rusting?
Water + oxygen + IRON (only happens to iron)
How does tarnishing occur?
with quite reactive metals - a protective oxide layer forms to avoid corrosion (this is a tarnish) which prevents further reaction
What is the process of a Life Cycle Assessment
1 - extracting and processing raw materials (is material renewable on finite?)
2 - Manufacturing and packaging (energy costs money)
3 - Use and operation during it’s lifetime (how long does it last, efficiency)
4 - Disposal at the end of it’s useful life time (landfills, recyclability)
How are metals extracted with electrolysis?
The molten ore is dissolved in molten cryolite at 950 degrees - the molten metal is kept in a steel cell with graphite cathode lining and graphite anodes
