Metals Flashcards
What happens when alkali metals react with water
When an alkali metal reacts with water, metal hydroxide and hydrogen gas are formed.
Metal + water= metal hydroxide + hydrogen
What is the reactivity series?
Potassium
Sodium
Lithium
Calcium
Magnesium
Ali minimum
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold
What forms when a metal reacts with an acid?
A salt and hydrogen
Metal + acid = metal salt+ hydrogen
Why do Copper, silver and gold not react with acids
Hydrogen is in all acids and they are below hydrogen in the reactivity series.
What is a displacement reaction?
A more reactive metal takes the place of a less reactive metal from its compound
Describe the thermite reaction
Aluminium + iron oxide= aluminium oxide + iron
The magnesium acts as a fuse and together with the igniter mixture provides the energy needed for the reaction to take place.
What must you have for rusting to occur
For rusting to occur you need oxygen, water and iron must be present
What is the chemical equation for rusting
Iron + water + oxygen = hydrated iron (lll) oxide
What are the 3 methods of rust prevention
Barrier method
Sacrificial protection
Galvanising
What is the barrier method? Disadvantages and examples
Coating of iron with a barrier of grease, oil, paint or plastic, it is cheap but if the coating breaks iron will rust so has to be frequently replaced. Eg. Bicycle, food cans
What is sacrificial protection, disadvantages and examples?
Blocks of a more reactive are placed on iron. The more reactive metal reacts instead of the iron. The sacrificial anodes have to be replaced when all of the metal has been oxidised. Eg. Hulls of ships, large metal structures.
What is galvanisation? Disadvantages and eg
Iron is coated in a layer of zinc. It has double protection as the zinc acts as a barrier to the iron but if it became scratched it would still protect as zinc is more reactive then iron.eg. Bridges. Watering cans
What is the difference for corrosion and rusting
Rusting only occurs with iron but corrosion occurs with all metals
What is the acronym for the reactivity series?
Please
Stop
Licking
Cold
Metals
Adam
Cold
Zebra
in
tiny
local
hospital
What salts do the different acids make?
Hydrochloric acid - metal chloride
Nitric acid- metal nitrate
Sulfuric acid - metal sulfate,