Rust is caused when iron comes into direct contact with water and oxygen. Technically, rust comes from a chemical reaction between carbon dioxide from the air, water and the iron. Rusting is an oxidation reaction.
The formation of rust represents a chemical change. When a chemical change occurs, the substance or substances present at the beginning are no longer present at the end of the change. Once a chemical change occurs, it theoretically cannot be undone.
Steel rusts because of chemical reactions that occur when it comes into contact with water and oxygen. Iron, one component of steel, combines with water and oxygen to produce hydrated iron (III) oxide, which is the chemical that we call rust.
Silver can rust or tarnish over time because of exposure to moisture or sulfur in the air. Tarnish and rust can cause silver to darken and look like it is black.
Copper undergoes a process much like rusting. When exposed to air for extended periods of time, copper oxidizes in a way similar to how iron forms rust. When copper oxidizes, certain chemical reactions form a light green layer over the copper.
Rust is not toxic in small doses, but can be toxic if a large quantity is ingested or if it enters the body intravenously. Any doses greater than 100 to 200 milligrams per kilogram could be considered lethal.
Some solutions to clean rust include mixing salt with lime or using baking soda with water. Another solution uses white vinegar and aluminum foil. It is best for individuals to apply these solutions with a soft brush, such as a toothbrush, instead of something abrasive, like steel wool.
Rust-removing chemicals containing hydrochloric or phosphoric acid; nontoxic, acid-free soaking solutions; and liquid or spray rust converters are good products to remove rust from metal. An alternative to chemicals is a power tool, such as a drill, oscillating tool, sander or a grinder, equipped wi
Technically, aluminum does not rust. However, a layer of oxide forms over the metal to protect it against further corrosion. This layer bonds strongly to the metal, is self-repairing if damaged and holds up well under conditions that are strongly acidic or strongly alkaline.
Fe2O3, or rust, is iron oxide formed by a redox reaction of iron and oxygen in the presence of water. Iron is the reducing agent, as it gives up electrons, while oxygen is the oxidizing agent gaining electrons. Simply expressed, Fe plus H2O plus O2 yields Fe2O3.