C15 - using our resources Flashcards
(16 cards)
Reaction for extraction of iron from iron oxide
Iron oxide + carbon —> Iron + carbon monoxide
Fe2O3 + 3C —> 2Fe + 3CO
What is rusting (iron) and steps - half equations
Oxidation of Iron when exposed to water and oxygen
2 steps:
Fe —> Fe2+ + 2e-
Fe2+ —> Fe3+ + e-
Electrons accepted by water and oxygen (2H2O + O2 + 4e- —> 4OH-
How can you prevent rusting
Galvanising (coating in zinc)
Coating in paint or oil to prevent oxygen touching it
Wrapped in more reactive metal or magnesium pouch for that to react instead (sacrificial metal)
What is rusting called in other metals (not iron)
Corrosion
How do you extract metals more reactive than carbon
Electrolysis
How do you extract metals less reactive than carbon
Burning with carbon
What is phytomining
Extracting copper from the ground by planting plants there then burning them
What is bioleaching
Bacteria break down copper ore to copper sulfate which can be electrolysed to get copper
What ore is aluminium from, and what catalyst do you use
Bauxite, dissolved in cryolite catalyst
What is the haber process and why is it needed
Process to make ammonia, used for fertilisers and explosives
Haber process steps
Nitrogen and hydrogen from the air and methane respectively are reacted at 450 degrees and high pressure with an iron catalyst, then the ammonia is separated off as a liquid
Haber process reaction equation
N2 + 3H2 <=> 2NH3
Conditions for Haber process and why
Medium temperature as lower temp has higher yield as forward reaction is exothermic
High pressure as there is less molecules on the right side
Why is low density polyethene softer than high density polyethene
LDPE has branches on the polymer chains which spreads it out, HDPE is dense and crystalline with chains parallel to each other
What is glass
Sodium carbonate (sand) heated
What is ceramic
Clay heated in kiln
