Making Pennies Clean
Pennies are shiny when their new, but after time they start to become dull. The one-cent coin was legal tender by the coinage act of 1864 (pennies.org). Abraham Lincoln is on the coin, and was put on the coin in 1909 (pennies.org). The penny was the first U.S. Cent to include the words “in God we trust” (pennies.org). Now how do they become dull and dingy?
Pennies become dirty because their copper. The copper and oxygen mixes to form copper oxide. Copper oxide is also known as cuprous oxide. Cuprous oxide occurs naturally in some parts of the world as cuprite (wisegeek.org). Cuprite is used in many other substance such as glucose and some types of sugars. Have you ever wondered why the Statue of Liberty is green? Well what. Happens is the copper turns green because of a chemical reaction that happens between the elements. The open air corrodes and forms a flakey orange-red layer on the outside of the copper (livescience.com). Than it undergoes a series of chemical reaction that gives the shines metal a greenish-blue outer layer called a patina. “Patina is a green substance the naturally forms on copper and bronze, sometimes called verdigris, usually consist of varying mixtures of copper chlorides, sulfides, sulfates and carbonates, depending …show more content…
When that film comes off your pennies will be as clean as can be. But how does salt and vinegar make the pennies clean?
Salt isn't the main thing in the cleaning process. All the salt does is speeds up the process of the removal. Copper oxide is soluble in acid.
The copper surface is oxidized, which slows down the formation of coper acetate (chemistry.org). When the chlorides is added to the solution, the chloride goes into the oxide layer and makes a hole in the layer that allows acetate to react with the