Topic 4- Extracting metals and equilibria Flashcards
How do different metals react with water?
reactivity
Most reactive metals react with water:
-Potassium, sodium, litium react violently
Mildly reactive:
-Magnesium only reacts slowly or with steam
-Zinc + iron react only with steam
Unreactive:
-Copper, silver, gold
most= hydroxides + hydrogen formed
How do different metals react with water?
Highly reactive: dangerouse
-Potassium, Sodium
Midly reactive:
-Produce hydrogen and chlorides
-Magnesium, zinc, iron
Unreactive:
-Copper, Silver, Gold
How do displacement reactions show reactivity series?
-more reactive= displace the salt
What is the reactivity series?
Pottasium
Sodium
Lithium
Calcium
Magnesium
Alluminium
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold
Platinum
Describe how lithium reacts with water?
-Floats and fizzes
-Hydrogen produced
-Alkaline due to lithium hydroxide + hydrogen
Describe how sodium reacts with water?
-Melts into ball
-Fizzes more rapidly
-Moves quickly across surface
-Strong alkaline=hydroxide
Describe how potassium reacts with water?
-Lilac flame
-Moves rapidly
-Fizzes rapidly
-Stronger alkaline=hydroxide
Describe how rudbidium reacts with water?
-Very voilent + explosion
-Burst into flames (hydrogen ignites)
-Hisses
-Stronger allkaline
Describe how cesium reacts with water?
-Most voilent explosion
-Burst into flames
-One of the strongest bases formed
What is a displacement reaction?
-Redox reaction
-One metal looses electons (becomes salt + oxidation)
-One metal gains electrons and is displaced (reduction)
Where are most metals found?
-In the crust in ores (more than one element)
-Some unreactive metals are found as uncombined elements in the crust
What is oxidation?
-Element looses electrons and becomes a cation
What is reduction?
-Element gains electrons and becomes an anion
What are ores?
-A mix of metal and other compounds (naturally forming rock)
-That is economically viable to extract the metal from
normally oxidised
How to extract metals from ores?
-Displacement reaction
-Reduction of ores
What are the method to extract metals from ores due to its reactivity?
Heating with carbon:
- Metals less reactive than carbon
- Carbon wil displace
- Will displace oxygen from oxide to produce carbon monoxide
Electrolysis:
- More reactive than carbon, carbon will not displace it
carbon is cheaper, so economically viable
Reduction of iron oxide equation?
heated with carbon
Fe2O3+3C→2Fe+3CO
carbon monoxide is dangerous so oxygen is added to make CO2
Electrolysis of alluminium and equation?
-Molten
-Al is reduced at Cathode (gains electrons) Al 3+
-Oxygen is oxidised at Anode O2-
-2Al2O3—>4Al + 3O2
How to make electrolysis more economicallly viable?
-Cryolite
-Reduces aluminium melting point
What are two other ways to extract metals?
not displacement or electrolysis
-Bioleaching
-Phytoectraction
What is bioleaching?
-Convert metal sulfides into soluable metal ions and sulfuric acid
-By oxdation
-This can then be further seperated through dsplacement or electrolysis
CuS–> CuSO4
What is phytoextraction?
-Plants grown in low concentration of metal soil
-Absorb nutients then burned
-Metal rich ash
-Metal then extracted from ash through electrolysis and displacement
Example of bioleaching?
Copper:
CuS+O2→Cu (2+) +SO4 (2−)
-Oxidation
-Copper then displaced by scrap ion
Example of phytoextraction?
-Nickle extraction
-Alyssum absorbs it
-Concentrated in leaves
Benefits and disadvantages of bioleaching?
Benefits:
-Cheaper
-Better for environment than digging
-Extracts from low grade ore
Disadvantages:
-Takes a long time
-Produces toxins
Benefits and disadvantages of phytoextraction?
Benefits:
-Absorbs soil contamination
-Cheaper
-Better for environment than mining
Disadvantages:
-Plants take ages to grow
-Burning cuases fossil fuels
-Takes up a lot of land
Why are metals resistent to oxidation?
-More reactive= Easier to be oxidised (easier to loose electrons)
-Less reactive= Resistent to oxidation (gold rarely oxidised, can be found pure in crust)
Benefits of recycling metals?
Economic:
-Creats jobs in collection + processing
- Less energy then extracting from ore
Environmental:
-No mining
-Less CO2 emmisions as no mining
-Reduce landfill
Preserving raw materials:
-Finite e.g copper
What is the lifecycle of a metal?
Obtaining:
-Mining= destoy land + CO2
Manufacturing:
-Lots of energy/ electricity + water
-Produces waste
Transporting:
-Energy
Using:
-May use electricity
Disposing:
-Landfill
-Resused
