Chemical Changes Flashcards
The more reactive a metal is the more… - Reactions
The more vigorous its reactions are and the more easily it loses electrons to form positive ions
What happens when a metal reacts with water? - Reactions
A metal reacts with water to form a metal hydroxide and hydrogen
What happens when a metal reacts with a dilute acid? - Reactions
A metal reacting with a dilute acid would form a salt and hydrogen
What would happen if a metal reacted with oxygen? - Reactions
A metal reacting with oxygen would form a metal oxide
How can oxygen be removed from metal oxides? - Reactions
By reacting the oxide with carbon, carbon displaces the metal to form a metal and carbon dioxide
What are oxidation reactions? - Reactions
A reaction in which a substance loses electrons (OILRIG)
What is a reduction reaction? - Reactions
A reaction in which a substance gains electrons
What is a redox reaction? - Reactions
When reduction and oxidation occur at the same time within a reaction
What is an ore? - Reactions
A rock containing enough quantities of a mineral for extraction to be possible (economically viable)
Why is electrolysis expensive? - Reactions
It requires large amounts of electricity to perform
How can a metal be extracted from a compound if it is less reactive than carbon? - Reactions
By heating the compound with carbon, the metal is displaced because carbon is more reactive
Why must aluminium be extracted from compounds using electrolysis? - Reactions
Aluminium is more reactive than carbon and therefore cannot be displaced
Why must aluminium oxide be molten as an electrolyte during electrolysis? - Reactions
It is insoluble in water and therefore can only be used as an electrolyte when molten
Why does the electrolysis of aluminium oxide take especially high amounts of energy and is so costly? - Reactions
It has strong ionic bonds which are extremely difficult to break and require lots of energy to overcome
How is the cost reduced of melting aluminium oxide to form a molten electrolyte? - Reactions
Powdered aluminium oxide is dissolved in molten cryolite, and does so faster than if it were unpowdered. This costs less as a result.
What is an acid? - Reactions
A substance producing more hydrogen ions than hydroxide ions when dissolved in water