Take this Quiz: GCSE Chemistry: Electrolysis | Zestly

Question 1

Why must an ionic compound be molten or dissolved in water to conduct electricity during electrolysis?

Accepted Answer

The ions must be free to move to carry the charge.

Question 2

During the electrolysis of molten lead(II) bromide, which products are formed at the electrodes?

Accepted Answer

Lead at the cathode and bromine at the anode.

Question 3

Which of the following statements correctly describe the rules for the electrolysis of aqueous solutions?

Accepted Answer

Hydrogen is produced at the cathode if the metal is more reactive than hydrogen.

Question 4

In the industrial extraction of aluminium, why is cryolite added to the aluminium oxide?

Answer

To act as a catalyst for the reaction.

Answer

To lower the melting point of the mixture.

Answer

To prevent the carbon anodes from burning.

Answer

To increase the electrical conductivity of the solid.

Question 5

Why do the carbon anodes used in the electrolysis of aluminium oxide need to be replaced periodically?

Answer

They react with oxygen to form carbon dioxide.

Answer

They dissolve into the molten aluminium.

Answer

They are consumed by the cryolite.

Answer

They lose their shape due to the high current.