Extracting Metals And Equilibria Flashcards
What properties do the metals have at the top of the reactivity series?
Potassium, sodium and calcium are the 3 at the top of the reactivity series and reacts vigorously with water.
They easily form cations and are less resistant to oxidation.
What properties do metals have at the bottom of the reactivity series?
Copper, silver and gold are at the bottom and do not react with water or dilute acid.
Do not easily form cations.
More resistant to oxidation.
What is a displacement reaction?
A displacement reaction is when a more reactive element takes places of a less reactive metal in a compound.
What is a Redox Reaction?
A redox reaction is where one substance in a reaction is reduced and another is oxidised.
Oxidation= Gain of oxygen but Loss of electrons.
Reduction= Gain of electrons but Loss of oxygen.
How are metals extracted?
Most metals are extracted from ores taken from the Earths crust.
Electrolysis- used for metals more reactive than carbon, requires a lot of energy so is expensive only used for reactive metals.
Reduction using carbon- can only be used to extract metals less reactive than carbon.
How is aluminium extracted by electrolysis?
The aluminium goes to the cathode (-) and molten aluminium metal is formed.
Molten aluminium oxide mixed with cryolite (to lower the melting point)
Oxygen gas is formed at the anode (+)
What is the issues with extracting metals?
- Metals are non- renewable resources- they will eventually run out.
- mining metals damages the environment.
- fossil fuels need burning to provide lots of energy for extraction, causing pollution. (Non- renewable)
What are the benefits of recycling metals?
- Reduces the amount of waste sent to landfill.
- Reduces the need for mining- preserves finite amount of metal.
- uses less energy than mining and extracting raw materials.
- often cheaper to recycle than extract more metal. Recycling also creates lots of jobs.
What is Life Cycle Assessments?
An assessment of the environmental impact of a product over a stage of its life.
Raw materials —> Manufacturing—> using the product —> product disposal
Considerations:
Metals need mining and extraction from ores.
Can cause pollution.
Damage to environment.
Landfill takes up space.
What is Equilibrium?
Dynamic Equilibrium- the forward and backward reactions are both happening at the same rate.
Equilibrium can only be reached when a reversible reaction takes place in a closed system (where nothing can enter or leave).
If higher the concentration of REACTANTS than PRODUCTS: equilibrium lies to the LEFT.
If higher concentration of PRODUCTS than REACTANTS: equilibrium lies to the RIGHT.
What is the Haber Process?
N2 (g) + 3H2 (g) —> 2NH3 (g)
< —
N2- obtained from the air
3H2- extracted from hydrocarbons
2NH- ammonia produced
Conditions:
- 450°C
- 200 atmosphere
- iron catalyst
What is Le Chatelier’s Principle?
If the conditions of a reversible reaction at equilibrium are changed, the system tries to counteract that change.
TEMPERATURE INCREASES ENDOTHERMIC direction to TAKE in the heat energy.
TEMPERATURE DECREASES EXOTHERMIC direction to RELEASE heat energy.
PRESSURE INCREASES side with FEWER moles of gas to REDUCE the pressure.
PRESSURE DECREASES side with MORE moles of fed to INCREASE the pressure.
If the concentration of a reagent is changed, the system will respond to reverse the change.
If the concentration of REACTANTS INCREASES the system responds to make MORE PRODUCTS.
if the concentration of REACTANTS DECREASES the system responds to make MORE REACTANTS.
