Electrolysis Flashcards
When are ions free to move about in ionic substances?
When the ionic substance is melted or dissolved within a liquid or solution.
How do you break down an ionic substance solution into elements?
By passing a current through the substance that is molten or a solution.
What is electrolysis?
When you pass a current through ionic substances that are molten or a solution so that it can be broken down into elements.
What is the electrolyte?
The substance being broken down in electrolysis.
Where do the positively charged ions move to during electrolysis?
The negatively charged electrode (cathode).
What is the negatively charged electrode called?
Cathode.
Where do the negatively charged ions move to during electrolysis?
The positively charged electrode (anode).
What happens at the electrodes?
Ions are discharged producing elements.
What happens when a simple ionic compound is electrolysed in the molten state using inert electrodes?
The metal is produced at the cathode and the non-metal is produced at the anode.
This is because the metal is the positive ions and the non-metal is the negative ions.
When is electrolysis used on metals?
When the metal is more reactive than carbon so can’t be extracted by reduction with carbon.
How are metals that are more reactive than carbon extracted?
By electrolysis of molten compounds.
How much energy is needed in the electrolysis of metals?
Large amounts of energy are used in the extraction process to melt the compounds and to produce the electrical current.
What is energy used for in electrolysis of metals?
To melt the compounds.
To produce the electrical current/
How is aluminum manufactured?
Aluminium is manufactured by the electrolysis of a molten mixture of aluminium oxide and cryolite using carbon as the positive electrode (anode).
Why is aluminum oxide mixed with cryolite?
Aluminium oxide has a very high melting point, so it would be too expensive to melt it.
