Extracting metals and Equilibria Flashcards
What is Oxidation?
The addition of oxygen and loss of electrons.
What is Reduction?
The reduction of oxygen and gain of electrons.
What do Combustion reactions involve?
Oxidation.
What is Reactivity?
How easily positive ions form or how easily outer electrons are lost.
What Group in the periodic table has the most reactive metals?
Group 1 metals.
What happens when you react metals with acids?
You produce Salt and Hydrogen.
Most reactive metals produce the most…
Heat.
How do we compare the reactivity of the metals fairly?
By ensuring the metals have the same mass/surface area and that we use the same type and concentration each time.
What happens when you react metals with water?
You produce Metal hydroxide + Hydrogen.
What is a Displacement Reaction?
When a more reactive metal displaces a less reactive metal in a compound.
When metal reacts with acid, the more reactive the metal is…
the faster the reaction with the acid will go.
When very reactive metals react with acid what happens?
It will fizz vigorously. E.g. Magnesium
When less active metals react with acid what happens?
It will bubble a little bit. E.g. Zinc.
When unreactive metals are put in acid what happens?
It will not react at all.
How can you test for hydrogen?
Using a light splint.
The louder the squeaky pop… (lighted splint test)
The more hydrogen has been made in the time period and the more reactive the metal is.
What is the speed of reaction also indicated by?
The rate at which the bubbles of hydrogen are given off - the faster the bubbles form, the faster the reaction and the more reactive metal.
What is a metal ore?
A rock which contains enough metal to make it economically worthwhile extracting the metal from it.
What is the ore in the metal ore?
An oxide.
Where are most of the metals that we use found?
Their ores in the Earth’s crust.
Extracting metals from its ore chemically by reduction using carbon only work on metals…
Less reactive than carbon.
When an ore is reduced…
Oxygen is removed from it.
Metal oxide + Carbon ->…
Pure metal + Carbon dioxide
If the metal is more reactive than carbon how can it be extracted?
Using electrolysis of molten compounds.
In order to run electrolysis to extract materials from their ores, you need…
Large amounts of electricity.
Explain why metals lower down the reactivity series (less reactive than carbon) are cheaper to extract than those higher up the reactivity series.
In electrolysis, large amounts of electricity is needed which is expensive and there also additional costs with melting or dissolving the metal ore.
In comparison, extracting metals using reduction with carbon, is much cheaper. Carbon is cheap and also acts as a fuel to provide the heat needed for the reduction reaction to happen.
What is Bioleaching?
Uses bacteria to separate metals from their ores.
What is Phytoextraction?
Involves growing plants in soil that contains metal compounds.
What does Recycling metals save?
Energy.
How does recycling protect the environment?
Mines are damaging to the environment and destroy habitats. Recycling would mean we wouldn’t have to use so many mines.
Also cut down the amount of rubbish that gets sent to landfill. Landfill takes up space and pollutes the surrounding.
How is Recycling metals good economically?
Recycling is a massive industry and can create lots of jobs.
What does the Life Cycle Assessment do?
Looks at each stage of the life of a product. From making the product, manufacturing it, using it and then disposing it.
What is a Reversible reaction?
One where the products can react with each other to produce the original reactants.
What happens during the Haber process?
Nitrogen and hydrogen react to form Ammonia.
At what temperature is the Haber process carried out?
450 degrees celsius.
At what pressure is the Haber process carried out at?
A pressure of 200 atmospheres and an iron catalyst.
If there’s a change in concentration, pressure or temperature in a reversible reaction…
The equilibrium position will move to help counteract that change.
If you decrease the temperature…
The equilibrium will move in the exothermic direction to produce more heat.
If you increase the temperature…
The equilibrium will move in the endothermic direction to absorb extra heat.
If you increase the pressure…
The equilibrium will move towards the side that has fewer molecules of gas to reduce pressure.
If you decrease the pressure…
The equilibrium will move towards the side that has more molecules of gas to increase pressure.
If you increase the concentration of the reactants…
The equilibrium will move to the right to use up the reactants.
If you increase the concentration of the products…
The equilibrium will move to the left to use up the products.
What will decreasing the concentration do?
Have opposite effect.
