Question

Explain why the inside of cans are coated with a thin layer of tin or plastic.

Answer 1

Partly to keep the contents from reacting with the iron in the steel can and partly to keep the steel can from rusting.

Answer 2

different metals each have a different rate at which they corrode. According to a table referred to as the galvanic series, steel (which is what most cans are made of, typically food cans) is one of the most corrosive metals meaning that it will corrode faster than other metals. Tin is much less corrosive and therefore is used on the inside of steel food cans to protect the contents of the can.