C2.7 - Electrolysis Flashcards
What is electrolysis?
Passing an electric current through molten/dissolved ionic substances and breaking them down into elements.
What is the substance that is broken down in electrolysis called?
The electrolyte.
Where to positive ions move to in electrolysis?
The negative electrode.
Where to negative ions move to in electrolysis?
The positive electrode.
If there is a mixture of ions, what do the products depend on?
The reactivity of the elements involved.
What happens when a substance is oxidised?
Electrons are lost.
What happens when a substance is reduced?
Electrons are gained.
What are objects electroplated? (2)
- To make items look more attractive (e.g. silver).
2. To make objects conduct electricity (e.g. copper).
How is aluminium removed from its ore?
Electrolysis.
What is aluminium oxide dissolved in for electrolysis and why?
Cryolite, in order to lower the temperature from over 2000 degrees to around 900 degrees, making the process cheaper and easier.
What is formed at the positive electrode in the electrolysis of aluminium oxide, and what does this produce?
Oxygen, and carbon dioxide because the electrode is made from carbon.
What is formed at the positive electrode in the electrolysis of aluminium oxide?
Aluminium.
What is produced during the electrolysis of sodium chloride? (3)
- Hydrogen.
- Chlorine.
- Sodium hydroxide solution.
What can sodium hydroxide solution be used for?
The production of soap.
What can chlorine be used for?
The production of bleach and plastics.
