Chemistry In Industry Flashcards
How are most metals found?
in their ores
in the Earth’s crust combined with other elecments
the individual compounds are called minerals
What is a metal ore?
a metal ore is a compound that contains enough the mineral for it to be economically viable to extract some metal
What is the price of a metal affected by>
how common the ore is
how difficult it is so extract the metal from its ore
There is a limited/unlimited amount of metal ores - they are … resources
There is a limited amount of metal ores - they are finite resources
The more reactive a metal is, the easier/harder it is to extract it from its compound
The more reactive a metal is, the harder it is to extract it from its compound
What are native metals?
very unreactive metals, such as godl, that exist naturally as the uncombined element (you just have to find them and dig them up)
silver and copper are also sometimes found native - although much more rarely
What do metals often have to be separated from?
their oxides
How to metals form oxides?
lots of metalls, like iron and aluminium, react with oxygen to form oxides
these oxides are often the ores that the metals need to be extracted from
What is the name of the reaction that separates a metal from the oxygen it its oxide?
a reduction reaction
e.g. 2CuO + C → 2Cu + CO2
The most common type of reduction reaction uses … as a reducing agent to separate the oxygen from the metal
The most common type of reduction reaction uses carbon as a reducing agent to separate the oxygen from the metal
Metals exist as positive ions in their …. To produce the metal you would have to …. This is called …
Metals exist as positive ions in their ionic compounds. To produce the metal you would have to add electrons to the positive ion. This is called called reduction
What is ‘roasting’?
converting a metal compound into an oxide by heating in air
What are the two main economic factors to take into account when deciding on the method of reducing an ore to the metal?
the cost of energy
the cost of the reducing agent
How are some metals, such as titanium, extracted? Is this expensive? Why?
by heating thecompound with a more reactive metal
this is expensive, because the more reactive metal itself will have to be extractedby an expensive process first
How are metals below carbon in the reactivity series extracted? Is this expensive? Why?
they are extracted by a reduction reaction by heating the metal ore with carbon or carbon monoxide
this is the cheapest method of reducing the ore
carbon is cheap and can also be used as the source of heat
How are metals above carbon in the reactivity series extracted? Is this expensive?
by electrolysis
the large amounts of electricity involved make this an expensive process so a metal like aluminium is much more expensive than one like iron
