Q.Write short note on chrome plating.

Chrome plating deposits a thin, hard, corrosion-resistant, bright layer of chromium onto a base-metal article by electrolysis.

Chrome plating (chromium electroplating) is an application of electrolysis used to coat a base metal object (commonly iron, steel, or brass articles such as automobile parts, taps, and bicycle handlebars) with a thin, adherent layer of metallic chromium.

Procedure: the article to be plated is first thoroughly cleaned, and is usually given an undercoat of copper and then nickel plating to give a smooth, level base and improve adhesion and corrosion resistance. It is then made the cathode in an electrolytic cell containing a bath of chromic acid ($CrO_3$) dissolved in dilute sulphuric acid (which acts as a catalyst). An insoluble lead or lead-antimony alloy plate is used as the anode. On passing a direct electric current, chromium (from the chromic acid in solution) is deposited as a thin, hard, bright metallic layer on the cathode (the article).

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