C15 Flashcards
what is corrosion
caused by chemical reactions between the metal and substances in the environment
what is rusting
the corrosion of iron
what is rust
form of iron(III) oxide called hydrated iron(III) oxide
what is the reaction for rusting
iron + oxygen + water -> hydrated iron(III) oxide
how can we prevent corrosion
coating the metal with paint, grease or plastic can
how does coating the metal prevent rusting
forms a protective barrier around the metal from oxygen and water
what is galvanised iron
iron covered with a layer of zinc.
why is iron coated in zinc
as it is more reactive so any water or oxygen is more likely to react with it
what is sacrificial protection
zinc covering iron to prevent rusting
why does aluminium not corrode
a protective oxide layer forms on aluminium metal which protects the aluminium beneath
what is bronze used for
alloy of copper and tin
used to make statues and ships propellers
what are features if bronze
tough and resistant to corrosion
what is brass and what is it used for
alloy of copper and zinc
much harder than copper and is used to make instruments, door fittings and taps
what is aluminium used for and why
it is lightweight for a metal with low density but strong
it is used to build air craft
what is gold and what is it used for
alloyed from silver copper and zinc
used in jewellery
what are steels
alloys of iron
how can the properties of steel be changed for different uses
controlling the amounts of carbon and other uses
what are carbon steels
high carbon steel is used in cutting tools and is strong but brittle
low carbon steels are used for car bodies and are softer and more easily shaped
what are stainless steels
such as chromium and nickel
combine hardness and strength with resistance to corrosion
used in cutlery
