Extracting Metals Flashcards
All 6 cards in this deck
In terms of oxygen, what are oxidation and reduction?
Oxidation is the gain of oxygen; reduction is the loss of oxygen.
Where are most metals found, and how are unreactive metals such as gold and silver found?
Most metals are found as ores (compounds) in the Earth's crust; unreactive metals are found as the uncombined elements.
How is the method of extracting a metal from its ore decided?
e.g. iron oxide and aluminium oxide
- Compare the metal with carbon in the reactivity series.
- Less reactive than carbon → heat the ore with carbon: iron.
- More reactive than carbon → electrolysis: aluminium.
True or false? Extracting a metal from its ore always involves reduction of the ore.
True. The metal ions gain electrons / the ore loses oxygen.
Give one advantage and one disadvantage of extracting a metal by electrolysis rather than heating with carbon.
Advantage: it can extract metals more reactive than carbon (e.g. aluminium), which carbon cannot reduce. Disadvantage: it uses a large amount of electricity, so it is expensive.
What is a metal ore?
Rock with a high enough proportion of a metal compound that the metal can be extracted at a profit.
e.g. haematite, which contains iron oxide.