Question

What is anodising? Briefly explain anodising. [2 marks]

Answer 1

Anodising is one of the methods used for preventing rusting.[0.5 mark]

• During anodising process, dilute acid is taken into an electrolytic cell and aluminium article is dipped in it as the anode.[0.5 mark]
• On passing an electric current the hydrogen gas is released at the cathode and oxygen gas is released at the anode.[0.5 mark]
• A reaction of aluminium with oxygen occurs at the anode and a protective layer of hydrated aluminium oxide is formed on the metal surface.[0.5 mark]