Electrolysis Flashcards
When an ionic substance is melted or dissolved in water, ions are free to…
Move about within the liquid / solution
Electrolyte?
Substance broken down in electrolysis
Electrolysis?
Passing an electronic current through molten or solutions of ionic substances to break them down into elements
Where do positive ions move towards?
Negative electrode (cathode)
Where do negative ions move towards?
Positive electrode (anode)
What’s oxidation?
Losing electrons (negative ions)
What’s reduction?
Gaining electrons (positive ions)
What happens at the cathode if hydrogen ions are present?
The metal ions stay in solution if they are more reactive than hydrogen
If there’s a mixture of ions in the electrolyte, what do the products formed depend on?
The reactivity of the elements involved
What happens at the anode when hydroxide ions and halide ions are present?
Molecules of chlorine, bromine or iodine will form
What happens at the anode when only hydroxide ions are present?
Oxygen forms
Why do metals more reactive than hydrogen stay in solution?
As they are keener to stay as an ion
Which electrode do you put an item to be electroplated at?
Cathode- attracts positive ions
What are 2 uses of electroplating?
Decoration- (silver plating) cheap
Conduction (copper plating)
When making aluminium in electrolysis, what’s the anode made from?
Carbon
