1) Extracting Metals and Equilibria Flashcards
what is the equation for when a metal reacts with water?
metal + water
metal hydroxide +hydrogen
what happens when a metal reacts with water? example.
- more reactive faster the reaction
- magnesium fizz vigorously
- copper has no reaction
what are displacement reactions?
- redox reactions
- including the loss or gain of electrons
what is oxidation?
loss of electrons
-moer reactive metal gets oxidised
what is reduction?
gain of electrons
-less reactive metal gets reduced
what is the order of reactivity series starting with most reactive?
- potassium
- sodium
- calcium
- magnesium
- aluminium
- carbon
- zinc
- iron
- hydrogen
- copper
- silver
- gold
how are most metals extracted as from the earth?
most metals are extracted form ores found in Earth’s crust
where are unreactive metals found?
unreactive metals ae found in the earth’s crust as the uncombined elements
what does the extraction of metals involve?
the extraction of metals involves reduction of ores
how are metals higher in the reactivity series extracted and how extensive is it?
- extracted using electrolysis
- expensive
- potassium, sodium, calcium, magnesium, aluminium
how are metals lower than carbon extracted and how expensive is it?
- reduction using carbon
- i.e iron oxide is reduced
- zinc, iron, tin, copper, silver
what metals are found as uncombined elements?
silver and gold
what are two other biological methods of extraction that can be used?
bioleahing and phytoextraction
why are biological methods of extraction used?
-extracting metals out of ores which have small amounts of the metal
what is bioleaching?
- using bacteria
- bacteria gets energy from the bonds in the atoms separating them
what is phytoextraction?
- growing pants in soils containing metal compound
- metals build up in leaves
- plants harvested, dried, burnt
- metal extracted out of ash by electrolysis
how does the metals position in the reactivity series relate to oxidation?
- most reactive metal is least resistant to oxidation
- least reactive metal is most resistant to oxidation
what are the advantages of recycling?
- economic benefits
- protects environment
- conserves raw materials
how does recycling metals save raw materials?
- extracting metals uses fossil fuels
- so recycling would reduce the use of fossil fuels
- small fraction of energy used
how does recycling metals cause economic benefits?
- saves money, its expensive to extract
- recycling, big industry, so creates jobs
how does recycling metals help to protect the environment?
- mines damaging to environment
- destroys habitates
- pollutes surroundings
what is a life cycle assessment?
look at each stage of the life of a product.
what are the 4 stages in a life cycle assessment?
- choice of material/raw materials
- manufacture
- produce use
- disposal
all chemical reactions are…
reversible
what is dynamic equilibrium?
when forward and backward reactions are taking place at the same time and at the same rate and the concentrations of the reactants have balanced and wont change
what is the harbour process?
example of a reversible reaction
what is the temperature, pressure and cataleyist of the harbour process?
- temp= 450 degrees
- pressure= 200 atmospheres
- iron catalyst
how will the position of the dynamic equilibrium change if the temperature changes?
- decrease temperature move in exothermic direction
- increase temperature move in endothermic direction
how will the position of the dynamic equilibrium change if the pressure changes?
- increase pressure move to side with fewer moles of gas
- decrease pressure move to side with more moles of gas
how will the position of the dynamic equilibrium change if the concentration changes?
- increase concentration of reactants, move right
- increase concentration of products move left
- decreasing is opposite
