Electrolysis Flashcards
What is electrolysis?
The decomposition of a liquid electrolyte using a direct current of electricity.
What is electrolyte?
A liquid/solution that conducts electricity and is decomposed by it.
In electrolysis, the electrodes is sometimes made out of…?
Graphite
Inert means..?
Unreactive
Particles that move and carry charge are called?
Ions
When molten lithium undergoes electrolysis the products are..?
Lithium and chlorine
When aluminium is extracted by electrolysis the metal forms at..?
The cathode
Why can molten calcium fluoride conduct electricity?
As the ions are free to move and carry charge.
What happens to molten calcium fluoride when electricity passes through?
It breaks down/decomposes
Why is calcium produced at the cathode?
As calcium atoms have a +ve charge so are attracted to the -ve cathode
How is calcium produced at the cathode during electrolysis?
Calcium ions go to cathode and gain 2 electrons to form a calcium atom.
Ca2+ +2e- =Ca
What makes graphite a suitable material for electrodes?
Good conductor
Inert
Very high melting point
Cheap
What type of particle moves the charge in copper?
Electron
What type of particle moves the charge in sodium chloride solution?
Ion
What effect does copper have on the passage of electricity?
No effect
What effect does sodium chlorine have on the passage of electricity on the conductor?
Conductor breaks down
What is the half equation for the reaction of molten lithium chloride undergoing electrolysis?
Li+ + e- =Li
What is the half equation for when molten lead undergoes electrolysis?
2Br- + 2e- = Br2
Why is lead a good choice to demonstrate electrolysis?
Low melting point
‘Safe’ temp to be carried out at school
Form unreactive metal
During the extraction of aluminium from its ore, that is the name of the ore?
Bauxite
What is the half equation for heat happens at the cathode when aluminium is extracted from its ore.
Al3+ + 3e- = Al
Why do anodes need to be replaced periodically during the process of aluminium being extracted from its ore?
As they are made of carbon and react with the O2 produced to form CO2
