Electrolysis Flashcards
What is electrolysis?
The breaking down of a compound using electricity.
What is the positive electrode called?
The anode
What is the negative electrode called?
The cathode
What must the electrodes be made of and why?
A solid that conducts electricity but is inert.
What are electrodes usually made of? (examples)
Graphite - cheap
Platinum - expensive
What is the electrolyte?
The substance to be broken down. It needs to conduct electricity.
What type of compounds conduct electricity?
Ionic compounds that are molten or dissolved so the ions are free to move.
Why are the positive ions called cations?
Because they are attracted to the negative cathode.
Why are the negative ions called anions?
Because they are attracted to the positive anode.
What happens at the anode in molten electrolysis?
Non-metal ions lose electrons to form molecules.
What happens at the cathode in molten electrolysis?
Metal ions gain electrons to form atoms.
What happens at the anode in the electrolysis of aqueous solutions?
If a halide ion is present, that element is produced as per normal. Otherwise oxygen and water are produced.
What happens at the cathode in the electrolysis of aqueous solutions?
If the metal is less reactive than hydrogen, that element is produced as per normal. Otherwise hydrogen is produced.
