Reactivity Of Metals Flashcards
What is the order of the reactivity series?
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Hydrogen
Copper
Silver
Gold
Describe the reactivity series’ reactions with cold water, acid and oxygen.
Potassium:
Cold water - reacts violently
Acid - reacts violently
Oxygen - reacts quickly in air
Sodium:
Cold water - reacts quickly
Acid - reacts violently
Oxygen - reacts quickly in air
Calcium:
Cold water - reacts less strongly
Acid - reacts vigorously
Oxygen - reacts readily
Magnesium:
Cold water - slow reaction (reacts with steam)
Acid - reacts vigorously
Oxygen - reacts readily
Aluminium:
Cold water - slow reaction (reacts with steam)
Acid - reacts readily
Oxygen - reacts readily
Zinc:
Cold water - very slow reaction (reacts slowly with steam)
Acid - reacts less strongly
Oxygen - reacts
Iron:
Cold water - very slow reaction (reacts slowly with steam)
Acid - reacts less strongly
Oxygen - reacts
Copper:
Cold water - no reaction with water or steam
Acid - no reaction
Oxygen - reacts
Silver:
Cold water - no reaction with water or steam
Acid - no reaction
Oxygen - reacts
Gold:
Cold water - no reaction with water or steam
Acid - no reaction
Oxygen - no reaction
Describe a method to determine the order of reactivity.
Temperature change - the greater the temperature change in a reaction involving a metal, the more reactive the metal is.
Describe displacement reactions with metals.
A more reactive metal can displace a less reactive metal ion from its salt.
Describe the reactivity of aluminium.
Aluminium is high in the reactivity series, however, it doesn’t react with water and the reaction with dilute acids can be quite slow.
Why?
Because it reacts readily with oxygen, forming a protective layer of aluminium oxide which is very thin. The layer prevents reaction with water and dilute acids, so aluminium can behave as if it is unreactive.
Describe the thermal decomposition of metal compounds.
Metal carbonates:
Metal carbonate -> metal oxide + carbon dioxide
Metal hydroxides:
Metal hydroxide -> metal oxide + water
Metal nitrates:
Metal nitrate -> metal oxide + nitrogen dioxide + oxygen
Exception: group 1 metals
Describe thermal stability.
Group 1 carbonates are more thermally stable than those in group 2.
Therefore the group 1 compounds must be heated more to undergo decomposition.
Describe the rusting of iron.
Rust is a chemical reaction between iron, water and oxygen to form the compound hydrated iron(III) oxide (rust)
Oxygen and water must be present for rust to occur
During rusting, iron is oxidised
Describe the barrier method (rust prevention).
Prevents iron from coming into contact with water and oxygen. If coatings are washed away or scratched, iron is once again exposed.
Common barriers:
Grease
Oil
Paint
Plastic
Describe galvanising (rust prevention).
Process where the iron to be protected is coated with a layer of zinc.
Why?
Zinc is more reactive than iron, therefore it will lose its electrons more easily than iron - oxidised more easily than iron
