C6 - Electrolysis Flashcards
What does “Molten” mean?
A melted solid e.g. a liquid
What does “Cation” mean?
A positive ion
What does a ‘Anion’ mean?
A negative ion
What does “Cathode” mean?
A negative electrode
What does an “Anode” mean?
A postive Electrode
What is an “Electrolyte”?
A molten ionic compound that is able to conduct electricty because their ions are free to move and carry charge
What does the term “Electrolysis” mean?
Splitting up an ionic compound using electricity
When an 1 is MELTED, the ions are 2 to move about within the liquid.
These liquids are able to conduct electricity and are called 3.
Passing an electric current through ELECTROLYTES causes the ions to move to the 4.
5 (positive ions) move to the 6 (negative electrode) and 7 (negative ions) move to the 8 (positive electrode).
lons are DISCHARGED at the electrodes producing elements.
This process is called 9 - the breaking down of a compound by electricity.
1 - IONIC COMPOUND
2 - FREE
3 - ELECTROLYTES
4 - ELECTRODES
5 - CATIONS
6 - CATHODE
7 - ANIONS
8 - ANODE
9 - ELECTROLYSIS
What are electrodes?
Solid conductors made of metal or carbon
What happens first during electrolysis?
An electric current is passed through an electrolyte so the ions move toward the electrodes where they react and displace into neutral atoms
What happens first during electrolysis?
An electric current is passed through an electrolyte so the ions move toward the electrodes where they react and the compound decomposes
What happens to the ions in electrolysis after the compound decomposes?
The positive ions move towards the cathode and gain electrons
The negative electrons move towards the anode to lose electrons
When the positive ions in electrolysis move towards the cathode and gain electrons, what we say they become?
Reduced
When the negative ions in electrolysis move towards the anode and lose electrons, what do we say they become?
Oxidised
What happens when +/- ions get to the electrode?
They become discharged (neutral ions)
Why cant ionic compound solids be electrolysed?
The ions cant move freely so cant conduct electricity
Why is the extraction of metal from ores expensive?
Requires alot of energy
Why is aluminium mixed with cryolite when extracting it from bauxite ore?
Cryolite reduces almuniums very high melting point
What is the ion equation happening in the negative electrode when extracting aluminium oxide from bauxite?
Al3 + 3e- > Al
What is the ion equation happening at the positive electrode when extracting aluminium oxide from bauxite?
2O2 —–> O2 + 4e-
What do metals react with to form metal oxides?
Oxygen
What does PANIC stand for?
Positve Anode
Negative is Cathode
Which side is the Anode and the Cathode in the process of electrolysis?
Anode - left
Cathode - right
What is the apparatus needed for the process of electrolysis?
A beaker full of an electrolyte
Two electrodes made up of metal or Carbon
A wire and power supply to connect the electrodes and generate electricity
What is the cheap way of removing oxygen from a metal oxide?
React the metal oxide with carbon
What are the disadvantages of removing oxygen from a metal oxide through carbon reaction?
It will only work with metals less reactive than Carbon
Releases CO2 as a product
Where is Aluminium oxide found?
Found in a solid called bauxite
Copper nitrate solution is blue.
Suggest why the blue colour of the copper nitrate solution fades during the
electrolysis.
The copper ions, that give the blue colour are removed
Give two reasons why graphite is used for the electrodes.
Graphite can conduct electricity
Graphite is inert
Explain the difference between the processes in electrolysis and in a chemical cell.
Electrolysis use electricity to produce a chemical reaction
Whereas
Cells use a chemical reaction to produce electricity
Copper nitrate solution is blue.
Suggest why the blue colour of the copper nitrate solution fades during the
electrolysis.
Copper ions are discharged
