Distinguish clearly between a) Galvanizing & Tinning b) Cathodic and anodic coating

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Distinguish clearly between a) Galvanizing & Tinning b) Cathodic and anodic coating

written 6.9 years ago by

vibhavarikulkarni • 510

modified 2.8 years ago by

yashbeer ★ 11k

engineering chemistry

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written 6.8 years ago by

vibhavarikulkarni • 510

modified 6.7 years ago by

awari.swati831 • 100

Sr.No.	Galvanizing	Tinning
1	Processof covering iron or steel,with a thin coat of ZINC to,prevent it from rusting.	Process of coating steel with a,thin coat of TIN to prevent it,from corrosion
2	Zinc protects iron sacrificially.,Since it is more electro-positive,than iron and does not permit iron to pass into the solution.	Tin protects the base metal iron,from corrosion due to its noble,nature and higher corrosion,resistance.
3	In galvanized articles, zinc continues to protect the underlying iron by galvanic cell action, even if the coating of zinc,is broken at any place	Tin protects underlying iron till the coat is intact. Any break in coating causes rapid corrosion of,iron.
4	Galvanized containers cannot be used for storing acidic foodstuffs as zinc reacts with food acid forming poisonous compounds	Tin coated containers and utensils can be used for storing any food stuff as tin is non-toxic and protects metal from corrosion
5	Ideal temperature is around 450 degree C	Ideal temperature is around 250 degree C
6	Ammonium chloride is used as flux	Zinc chloride is used as flux

Sr.No.	Anodic Coating	Cathodic Coating
1	It protects base metal,sacrificially	It protects base metal due to high corrosion resist. & noble behavior.
2	Coating metal is at lower,potential than base metal	Coating metal is at higher potential than base metal.
3	Corrosion of base metal does not increase even on breaking as it heals its film	Corrosion of base metal increases,if there is a break in coating
4	e.g. galvanizing i.e. Zn coating on iron/steel.	Tin coated containers and utensils can be used for storing any food stuff as tin is non-toxic and protects metal from corrosion

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