Question

Distinguish between anodic and cathodic coating 

Answer 1

	Anodic coating		Cathodic Coating
1	This type of coating protect base metal sacrificially.	1	This type of coating protect the base metal because of high corrosion resistance and noble behaviour
2	The coating metal is at lower electrode potential than base m etal.	2	The coating metal is at higher electrode potential than base metal.
3	Corrosion of base metal does not enhance even on breaking “anodic coating” as it heals its film	3	Corrosion of base metal enhances, if there is a small cut in coating
4	Eg. Galvanising i.e. Zn coating on iron/steel	4	Eg. Tinning i.e. tin coating on iron/steel/copper/brass.