A single displacement reaction, also known as a single replacement reaction, is used in many everyday applications including bridge building, hot water heating in homes and electrochemical reactions in batteries, according to Phoenix College's ChemistryLand. A single replacement reaction occurs when one substance replaces another in a chemical reaction.
A common single replacement reaction occurs when zinc and copper move from aquous solutions to solids in batteries after electrons to create power. Zinc gives up two electrons and copper gains electrons in single replacement reactions with electricity. ChemistryLand explains a "sacrificial metal" reaction stabilizes iron with regards to rebar in bridges and in hot water heaters. A rod in hot water heaters made of magnesium or zinc prevents corrosion of the iron body when the rod oxidizes instead of the iron. Zinc does the same thing for iron rebar when zinc chloride is formed instead of iron chloride to prevent the weakening of bridge columns over water.
A single replacement reaction occurs when a more active substance replaces, or displaces, a less active compound. The Chemical Education Digital Library states all single replacement reactions are oxidation-reduction reactions. The steel industry uses this type of reaction to replace iron out of ferric oxide. Coke, a type of carbon or coal, replaces iron to create pure iron atoms.