Electrolysis Flashcards
What are electrolytes?
Ionic compounds that are:
- in the molten state (heated so they become liquids), or
- dissolved in water
What is electrolysis?
A process where electrical energy (from a direct current supply) breaks down electrolytes
Which kind of electrical supply is always used for electrolysis?
Direct current (DC)
What is the name of the positively-charged electrode?
Anode
What is the name of the negatively-charged electrode?
Cathode
What is the name of the positively-charged ion?
Cation
What is the name of the negatively-charged ion?
Anion
Which electrode do cations move to?
The cathode
Which electrode do anions move to?
The anode
What happens to positive ions at the cathode?
They gain electrons
What happens to negative ions at the anode?
They lose electrons
What happens at the cathode in the electrolysis of lead bromide?
Pb2+ ions gain electrons at the cathode and become Pb atoms
What happens at the anode in the electrolysis of lead bromide?
Br- ions lose electrons at the anode and become Br atoms, which pair up to form Br2 molecules
What forms at the cathode in the electrolysis of calcium chloride?
Calcium
What forms at the anode in the electrolysis of calcium chloride?
Chlorine