Electrolysis Flashcards
What is electrolysis?
The splitting up of an ionic substance by passing an electric current through it.
What happens if you pass an electric current through an ionic substance that’s molten or in solution?
It breaks down into elements.
What is the electrolyte?
Liquid to conduct the electricity, usually the molten or dissolved ionic substance.
What does the electrolyte contain?
Free ions.
What conducts the electricity?
Free ions.
What happens at the negative electrode?
Reduction.
What happens at the positive electrode?
Oxidation.
What is reduction?
Gain of electrons.
What is oxidation?
Loss of electrons.
In the electrolysis of lead bromide, what is produced at the positive electrode?
Bromine.
In the electrolysis of lead bromide, what is produced at the negative electrode?
Lead.
What happens if there are more than two free ions in the electrolyte at the negative electrode?
Hydrogen will be produced unless the metal is less reactive than it.
What happens if there are more than two free ions in the electrolyte at the positive electrode?
If no halide is present, oxygen will be formed.
What does the electrolysis of sodium chloride solution produce?
Hydrogen, chlorine and sodium hydroxide.
In the electrolysis of sodium chloride, what is produced at the negative electrode?
Hydrogen.
In the electrolysis of sodium chloride, what is produced at the positive electrode?
Chlorine.
In the electrolysis of sodium chloride, what is left in the solution?
Sodium hydroxide.
In the electrolysis of sodium chloride, what is the half equation for the negative electrode?
2H+ + 2e- –> H2
What is chlorine used for?
Bleach and plastics.
What is sodium hydroxide used for?
Chemical industry and soap.
What is the main ore of aluminium?
Bauxite.
What is cryolite used for?
To bring the high melting point down.
What are the electrodes made of?
Carbon (graphite)
In the extraction of aluminium, what forms at the positive electrode?
Oxygen.
