Test tube P is the where both oxygen and are present.
In tube Q is present but is absent.
In tube Q is present but is absent.
Mmuae Afoforo a Wobɛpaw:
control
water
oxygen
What is corrosion?
THE PROCESS BY WHICH ARE SLOWLY BROKEN DOWN BY REACTING WITH SUBSTANCES IN THEIR
is the only metal element that can rust? (1 Point)
is the other element that is needed for iron to rust?
is the compound that is needed for iron to rust?
What two other chemicals are needed for iron to rust? (1 Point)
(I will need to mark this)
Rust is hydrated (1 Point)
The iron is being (1 Point)
Test tube P is the where both oxygen and are present.
In tube Q is present but is absent.
In tube Q is present but is absent.
In test tube P
In test tube Q
In test tube R
Rusting will occur
Rusting will not occur
Oxygen removed by the water?
The stops new oxygen from dissolving in the water?
calcium chloride can be used to remove the water from the air?
Where on the metal does corrosion take place?
The rust that forms on the surface flakes off to expose more to the oxygen and so further rusting can occur.
This can cause the whole sample to .
When aluminium a layer of oxide forms a that prevents further
What compound forms the protective layer on a piece of aluminium?
What are the two main methods for preventing rusting?
methods prevent oxygen and water from reaching the iron.
methods use a more reactive metal that reacts instead of the iron.
How does painting an object prevent rusting?
How does oiling or greasing an object prevent rusting?
How does electroplating with a less reactive metal (such as tin) object prevent rusting?
Zinc be used for sacrificial protection because
Galvanising work as a barrier method of protection because the zinc forms a that prevents the oxygen and water getting to the surface of the iron.
Galvanising works as a sacrificial method of protection because
Sacraficial protection.
Zinc is reactive than iron. (1 mark)
If the coating is scratched, zinc will instead of the iron because zinc is reactive. (1 mark)
In contrast, tin is reactive than iron.
If a tin coating is scratched, the exposed iron will , and the tin will not offer sacrificial protection. (1 mark)
corrode
more
Hint Steel is an alloy of iron made by mixing other elements with iron.
Adding different elements forms different types of steel that have different uses.
Sample 1 does not rust because is not present.
Sample 2 does rust becauseare both present.
Sample 3 does not rust because is not present.
Sample 4 does rust because are both present.
Hint air contains 21% oxygen
