Question 14
State why galvanization, tinning and chromeplating are used as three different processes for coating specific articles for prevention of rusting.
Galvanization, tinning and chromeplating are used as three different processes because:
In galvanization, iron sheets are dipped in molten zinc. Zinc being more active than iron, protects iron by forming zinc ions more readily. It is used for iron articles exposed to heavy moisture like roof sheds, buckets, tubs, etc.
In tinning, iron sheets are dipped in molten tin. It is used for edible applications instead of galvanization because zinc dissolves in food acids and makes poisonous compounds.
In chromeplating, iron articles are electroplated with chromium, nickle, tin, copper etc. It is used for decorative purposes. It is costly and used exclusively.
Hence, the three processes are different ways of preventing articles from rusting depending on their use.