4.4.3 Electrolysis Flashcards
What is electrolysis?
Electrolysis is the process where passing an electric current through electrolytes causes ions to move to the electrodes, resulting in the discharge of ions and production of elements.
What are electrolytes?
Electrolytes are liquids or solutions that can conduct electricity, formed when ionic compounds are melted or dissolved in water.
What happens to positively and negatively charged ions during electrolysis?
Positively charged ions move to the negative electrode (cathode), while negatively charged ions move to the positive electrode (anode).
What is produced at the cathode and anode during the electrolysis of molten lead bromide?
Lead is produced at the cathode and bromine is produced at the anode.
What is a safer alternative for practical work in electrolysis?
Anhydrous zinc chloride is a safer alternative for practical work.
Why is electrolysis used to extract metals?
Electrolysis is used to extract metals that are too reactive to be extracted by reduction with carbon or that react with carbon.
What is the role of cryolite in the electrolysis of aluminium?
Cryolite is used in the electrolysis of aluminium oxide to lower the melting point and improve conductivity.
What is produced at the cathode when an aqueous solution is electrolysed?
Hydrogen is produced at the cathode if the metal is more reactive than hydrogen.
What is produced at the anode during the electrolysis of an aqueous solution?
Oxygen is produced at the anode unless the solution contains halide ions, in which case the halogen is produced.
What do water molecules break down into during electrolysis of aqueous solutions?
Water molecules break down into hydrogen ions and hydroxide ions.
What are half equations in the context of electrolysis?
Half equations represent the reactions at electrodes during electrolysis, showing the gain or loss of electrons.
What occurs at the cathode during electrolysis?
At the cathode, positively charged ions gain electrons, resulting in reduction.
What occurs at the anode during electrolysis?
At the anode, negatively charged ions lose electrons, resulting in oxidation.
Provide an example of a half equation at the cathode.
2H+ + 2e- → H2
Provide an example of a half equation at the anode.
4OH- → O2 + 2H2O + 4e-
