Reactivity Series Flashcards
what is reactivity?
How reactive a substance is.
If it is highly reactive it will react quickly (and sometimes violently!),
if it has a low reactivity the reactions will be slow.
For example,
magnesium has quite a high reactivity – it will react quickly with acid,
but copper has a very low reactivity – it will not react with acid at all.
what is the reactivity series?
order of reactivity of the metals.
The most reactive metals are at the top and the least reactive at the bottom
Carbon and hydrogen are non-metals but are often included to help us to work out if a metal will react with acid and how it could be extracted.
why do some metals act more vigorously than others?
Metal ions are positively charged as they lose negative electrons.
Some metals give up their electrons more readily than others and are, therefore, more reactive.
We can use the reactivity series to tell if a metal is more reactive than others.
potassium is more reactive than iron.
what is a displacement reaction and what happens in it?
Displacement reactions are chemical reactions which involve a metal and a compound containing a different metal.
When a more reactive metal displaces (‘kicks-out’) a less reactive metal from a salt.
For example:
zinc + copper sulfate —–> zinc sulfate + copper
Zn + CuSO4 —-> ZnSO4 + Cu
Zinc is more reactive than copper so displaces it from the copper sulfate.
During a displacement reaction:
–the more reactive metal becomes less visible as it dissolves into the solution
–the less reactive metal from the salt coats the surface of the more reactive metal as it is displaced from its compound
How can we use the reactivity series to predict whether a displacement reaction will occur or not?
If a more reactive metal is used to displace a compound/salt with a less reactive element contained, the chemical reaction will take place and the more reactive metal will displace the less reactive metal in the salt/compound.
If there is no difference in reactivity or a less reactive metal is used to displace a more reactive metal from its salt/compound, the chemical reaction won’t take place.
e.g
iron oxide + aluminium → iron + aluminium oxide This will work as aluminium is more reactive than iron.
aluminium oxide + iron —-> aluminium + iron oxide This equation as wrong as this chemical reaction won’t take
place as iron is less reactive than aluminium
what is a metal ore?
A rock that contains enough metal to make it cost effective to extract.
extract…
To remove something.
For example when a metal is extracted, the metal is removed from a metal compound found in the metal ore.
smelting…
A method used to extract metals that are LESS reactive than carbon from a metal oxide
e.g. to extract iron from iron oxide.
The metal oxide is heated with carbon in a blast furnace. The carbon is more reactive than the metal so displaces it, producing the metal and carbon dioxide.
electrolysis
When electricity is used to split up a compound into elements.
This is the method is used to extract metals that are more reactive than carbon.
How do diagrams show displacement reactions?
During a displacement reaction:
–the more reactive metal becomes less visible as it dissolves into the solution
–the less reactive metal from the salt coats the surface of the more reactive metal as it is displaced from its compound
e.g.
magnesium + copper sulfate → magnesium sulfate + copper
The symbol equation is:
Mg + CuSO₄ → MgSO₄ + Cu
The diagram shows the displacement reaction between magnesium and copper sulfate.
native…
Some metals are so unreactive that they do not form compounds (e.g. gold), so are found as elements (on their own) in the Earth’s crust
– we call these metals native
