2023 · Q72
Which one of the following is not true for anodizing process?
General KnowledgeChemistry
- AIt makes aluminium corrosion resistant.
- BMetals like aluminium, titanium and magnesium can be anodized.
- CClean aluminium article is the anode and oxygen gas is evolved at the cathode.
- DIt is used in aircraft industry.
Explanation
Anodizing thickens the natural aluminium oxide layer, making aluminium corrosion-resistant (A true), and works for aluminium, titanium and magnesium (B true); it is used in the aircraft industry (D true). The false statement is C: the clean aluminium article is made the anode (positive electrode), where oxygen is evolved and the oxide film grows — oxygen is not evolved at the cathode (hydrogen is). Hence C is not true for anodizing.