Why does iron rust in soft drinks
Answers
Answer:
At first, it may seem scary that cola and other sodas are so acidic they can be used to clean metal. To see for yourself, leave a tarnished coin in a glass of soda overnight. When you remove it the next day it will be much cleaner.
Effect on Corrosion
Metals tarnish when they are oxidized, or lose electrons, generally due to the presence of and reaction with sulfur compounds or oxygen, depending on the metal, creating a coating of metal oxide or metal sulfide, which can look like rust, tarnish, or patina, to name a few common types of oxidation product. When tarnished metal is exposed to an acid, the metal's oxidation is reversed, removing the corrosion layer and thereby cleaning the metal. The level of acidity can be modest. Soda is ten times less acidic than lemon juice and far less acidic than your own stomach. However, this doesn't mean you should drink as much soda as you like. Having soda as a regular part of your diet can lead to health problems.
Answer:
Plastics, more accurately called polymers, are not metallic so they don't corrode as such. However, the do suffer from environmental degradation. Polymers degrade in the environment because some agent causes the covalent atomic bonding in them to break down.
So, Rusting takes place only due to the oxidation, when the water vapours react with the surface of the iron or a metal. In the plastic they do not react with the surface.So plastic does not get rusted