Metals Flashcards
What are the general physical properties of metals?
High density Good conductors Malleable Ductile High fixed points
What are the general chemical properties of metals?
Form basic oxides
Form positive ions
What is an alloy?
A mixture of metals
What is brass made of, its properties and uses?
Copper and zinc
Stronger and more resistant to corrosion
Electrical fittings, car radiators
What is bronze made of, its properties and uses?
Copper and tin
Harder, stronger and sonorous
Statues, springs, coins
What is stainless steel made of, its properties and uses?
Iron, chromium and nickel
Does not rust
Kitchen sinks, cutlery, chemical plant
Why are alloys stronger than metals?
The different sized metal atoms disrupt the crystal lattice and make the arrangement less regular - stops layers of sliding over each other when force is applied
Describe the order of the reactivity series?
K - Potassium Na - Sodium Ca – Calcium Mg – Magnesium C – Carbon Zn – Zinc Fe – Iron Pb – Lead H – Hydrogen Cu – Copper Au – Gold
Everything above hydrogen in the reactivity series can
displace hydrogen from its acids
Why does aluminum seem not reactive ?
It forms an oxide layer which adheres to metal and protects it
What are displacement reactions?
reactions in which metals compete for oxygen or anions
The bigger the difference in reactivity between the two metals ___
the faster the displacement reaction
What is the extraction method for metal ores above carbon?
Electrolysis
What is the extraction method for metal ores below carbon and above hydrogen?
Reducing via heating with Carbon or Carbon Monoxide
What is the ore for extracting iron?
haematite
Describe the process of extracting iron from haematite? (6)
1) Coke burns to form CO2 which heats the furnace
2) CO2 reacts with coke to form carbon monoxide
3) Carbon monoxide reduces iron (III) oxide to form iron
4) Heat from furnace decomposes limestone
5) Calcium oxide reacts with silicon (IV) oxide to form slag
6) Slag run off
The more reactive a metal ___ the higher
the tendency of a metal to form its positive ion
What is the ore for extracting zinc?
zinc blende/zinc sulfide
Describe the process of extracting zinc from zinc blende? (6)
1) Zinc blende roasted (with oxygen) to form zinc oxide
2) Zinc oxide heated w/ coke in blast furnace
3) Carbon reacts with oxygen to form carbon monoxide
4) Carbon monoxide reduces zinc oxide to zinc
5) Zinc oxide can also react directly with carbon
6) Zinc vapour carried and condenses and purified
Why is electrolysis of zinc sulfate now preferred over blast furnace method?
Produces purer zinc
Describe the conversion of iron into steel (5)
1) Molten iron from blast furnace poured into steelmaking furnace
2) Oxygen + calcium oxide blown through oxygen lance
3) Oxygen oxidises impurities (carbon, sulfur, silicon, phosphorus) - some escape as gas, some react with calcium oxide to form slag
4) Amount of carbon controlled by oxygen blown, more carbon, less carbon
5) Addition of other metals to form steel
What are the uses of high carbon steel and mild steel?
Mild steel: machinery and car bodies
High carbon steel: knives and blades
What are the advantages of recycling metal? (2)
saves land that may be used for extracting ores
conserves metal ores + raw materials
saves energy, less fuel is used
What are the disadvantages of recycling metal? (2)
collecting and storing materials costly
takes time and energy to collect waste materials
What are the uses of aluminum?
manufacture of aircraft (strength +low density) food containers (resistance to corrosion)
What are the uses of copper?
electrical wiring cooking utensils (malleable/good conductor of heat)
What are the uses of zinc?
galvanise iron (stop rusting)
How can different steel alloys be formed/controlled?
Change carbon content
What are three reasons why alloys are used?
Strength
Hardness
Resistance to corrosion
What is the pneumonic for the reactivity series?
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