Question

A process of forming a thick oxide of aluminium when aluminium is exposed to air. This coat makes it resistant to corrosion. Resistance can be improved by making a layer of oxide thinker. In this technique, the aluminium article is the anode, and the electrolyte is sulphuric acid. The anode reaction results in the formation of a black-coloured film of aluminium oxide on the anode. By putting appropriate dyes in the electrolytic solution, both coloured surface with the decorative finish is achieved. Kitchen articles like anodised such as pressure cookers, pans and frames of sliding windows are applications of this technique.

1. Name the anode and electrolyte used in this technique.
2. How can we make aluminium articles made resistant to corrosion?
3. Name the technique used to coat the aluminium articles.

Answer 1

1. In this process, the anode is an aluminium object to be coated, and the electrolyte is diluted sulfuric acid.
2. When aluminium oxide is applied to an object made of aluminium, corrosion resistance is increased.
3. The technique is known as 'Anodising'.