Extracting Metals And Equalibria Flashcards
(23 cards)
Products when a metal reacts with cold water
Metal hydroxide and hydrogen gas
What are the products when a metal reacts with steam
Metal oxide and hydrogen gas
Chemical, equation for the reaction that occurs when calcium reacts with cold water
Ca + 2H2O —-> Ca(OH)2 + H2
What are the products when a metal reacts with dilute acids
Salt and hydrogen
If a metal reacts with cold water what does it suggest about the reactivity of the metal
The metal is very reactive as only the most reactive can react wiht cold water
A metal reacts with oxygen but not acid or cold water, what does this suggest about its reactivity
Not very reactive as most metals react with oxygen
Name a metal which will not react with water, acid or oxygen
Gold
Describe and experiment that uses displacement to compare the reactivity of two metals
Add a solid metal to a salt solution (salt must contain a different metal)
If the solid metal is more reactive it will gradually disappear, displacing the metal that was in the salt solution
If nothing happens, the meta, in the salt is more reactive and can’t be displaced
What would you expect to observe when magnesium is added to copper sulfate
Copper sulfate solution is blue
Magnesium is more reactive than copper. So when magnesium is added the blue solution decolourises and copper coats the surface of the magnesium
Why can a displacement reaction be called a redox reaction
A redox reaction occurs when reduction and oxidation are taking place in the same reaction
In a displacement reaction, the more reactive metal atoms lose electrons to form ions (oxidation) and the less reactive metal ions gain electrons from the element (reduction)
The reactivity of a metal is related to its tendency to form ________
Cations (positive ions)
Which metals are most easily oxidised
The metals highest in the reactivity series. More reactive metals are more likely to react with water and dilute acids to form cations
Where are most metals extracted from
Ores in the earths crust
What is an ore
A rock which contains metals often chemically combines with other substances
Which metals are found in the earths crust as uncombined elements
Unreactive metals
Explain what oxidation means in terms of oxygen
Gain of oxygen
Explain what reduction means in terms of oxygen
Loss of oxygen
Most ores contain metals chemically combines with oxygen. What process must be carried out to extract the metal
Reduction
How can metals be extracted from their ores
- Reduction with carbon - can be done if the metal is less reactive than carbon
- Electrolysis - can be done with all metals but requires a large amount of energy which is expensive
How would you extract iron from its core
Iron is less reactive than carbon so can be extracted by reduction with carbon.
Electrolysis could be used but would use lots of unnecessary energy
Chemical equation for the reduction of iron with carbon
2Fe2O3 + 3C —-> 4Fe + 3CO2
How can aluminum be extracted from its ore
More reactive than carbon so electrolysis must be used.
When the molten ore undergoes electrolysis, the metal forms at the cathode
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