Topic 4 - Extracting metals + equilibria Flashcards
What is a metal ore?
A rock which contains enough metal to make it economically worthwhile extracting metal from it. Many cases the ore is an oxide of the metal.
What are some unreactive metals found in earths crust?
Gold, platinum. Present in earths crust as uncombined elements which can be mined straight out of ground but need to be refined for use.
How can a metal be extracted from its ore?
Chemically by reduction using carbon. When an ore is reduced, oxygen is removed.
What happens if metals are higher than carbon on reactivity series?
They have to be extracted using electrolysis which is expensive
What happens if metals are below carbon on reactivity series?
Can be extracted by reduction using carbon eg ion oxide reduced in blast furnace to make iron
Why can metals only be extracted using carbon if they’re below carbon?
Carbon can only take oxygen away from metals which are less reactive than itself
What are some uncombined elements?
Silver, gold
How does electrolysis extract metals?
Metal ore is melted + electric current passes through. Metal discharged at cathode and non metal at anode.
Bioleaching
Uses bacteria to separate metal from its ore. The bacteria get energy from bonds between atoms in ore , separating metal from ore in process
Phytoextraction
Growing plants in soil that contains metal compounds. Plants can’t get rid of metals so they build up on leaves. Plants harvested, dried + burned. Ash contains metal compounds where metal can be extracted using electrolysis.
When a metal reacts with an acid what should you see and what does this show about their reactivity?
More reactive the metal is, faster the reaction with acid will go. Reactive metals eg magnesium fizz vigorously. Less reactive metals bubble. Unreactive metals don’t react.
What happens when metals react with water and what does this show about their reactivity?
Reactive metals react vigorously with water. Less reactive metals won’t react much with cold water but will react with steam. Copper won’t react either way.
What are displacement reactions?
Redox reactions. Oxidation is loss of electrons and reduction is gain of electrons.
What is the reactivity series of metals?
Please stop calling me a crazy zebra instead try learning how copper saves gold.
Potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, tin, lead, hydrogen, copper, silver, gold
Explain why the reactivity series is ordered how it is in terms on oxidation.
Metals at top are most reactive. They can easily lose electrons to form cations, oxidised easily. Metals at bottom are less reactive as they don’t give up their electrons form cations as easily.
