Final answer:
Electroplating with tin protects tiffin containers from rusting, while chromium plating helps prevent rusting on car bumpers. These metals form protective layers hindering corrosion.
Step-by-step explanation:
Tiffin containers can be prevented from rusting by electroplating with tin, while rusting of car bumpers can be prevented by electroplating of chromium.
Electroplating is an electrochemical process where a layer of one metal is deposited on another. This technique enhances the appearance and prevents corrosion. For example, protective coatings such as chromium on bathroom fixtures and car bumpers, and tin coating on 'tin cans', protect the underlying steel from rusting. These metals create protective oxide layers that prevent oxygen and water from reaching the steel, thus preventing corrosion.
Prophylactic Protection:
Another method to prevent corrosion is to apply a physical barrier, such as paint, grease, or plastic. However, these are susceptible to damage, potentially allowing corrosion to begin. Metals like zinc or magnesium are used for cathodic protection because they are more readily oxidized and thus spare the iron from corroding.