9f Sculpture Park Flashcards
Is silver unreactive
Yes but it reacts very slowly with oxygen to form a black coating called iron oxide . It tarnishes
Copper reacts with oxygen to
Form a black coating of copper oxide then it further reacts to form a green coating of copper carbonate
Silver and copper oxides , tarnish or corrode
Tarnish
Iron reacts with oxygen to
Form iron oxide (rust ) which will then flake of leaving more iron exposed . Iron corrodes .
Unreactive metals are found in the environment as metals . Why are they expensive
they are rare
More reactive metals are common but found in ores as compounds and have to be extracted by
Heat or electricity
Word formula for oxidisation reaction
Metal + oxygen -> metal oxide
Hydroxide reaction
Metal + water -> metal hydroxide + hydrogen
Acidic reaction
Metal + acids -> salt + hydrogen
Sodium chloride ( salt ) melting point
800 degrees Celsius
How do we extract sodium from salt
We heat the salt to it’s melting point and the. Use electrical energy to break the bonds between the sodium and chlorine . This is called electrolysis
How do we stop corrosion
You can paint a metal however if the paint chips the metal will be attacked
You can galvanise it which is coating iron with zinc . Zinc reacts to form a insoluble layer of zinc carbonate . Even if this layer gets damaged the iron won’t rust right away as the zinc is more reactive . This is called sacrificial protection .
Reactivity series
Potassium sodium calcium magnesium aluminium zinc iron lead copper silver gold
What is a displacement reaction
Where a more reactive metal displaces a less reactive one
Aluminium + iron oxide -> aluminium oxide + iron
Can also take place in solutions
Iron + copper sulphate-> iron sulphate plus copper
Explain what happens when you place an iron nail into copper sulphate
A brown deposit of copper appears on the nail whilst the solution changes to a darker blue because iron has gone in it
