Answer to Question #28943 in Inorganic Chemistry for Jessica

Question

ships have zinc blocks welded to their hulls to prevent the hull rusting. explain how this works

Answer 1

It is galvanisation. Galvanisation is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc. In industry, the term GI stands for galvanized iron, referring to a common galvanized steel used in many applications such as air ducts and trash cans. Zinc is a more reactive metal than steel and is therefore oxidised instead of steel. Firstly to zinc oxide which then reacts again in carbon dioxide to form zinc carbonate.