Reaction type identifier
Enter a reaction to see what type it is, why, and which elements are oxidized and reduced.
Enter the full equation, balanced or not. States like (aq) or (s) are optional. Net ionic equations with charges work too, like Ag^+ + Cl^- -> AgCl.
The main reaction types
Synthesis: A + B → AB. Decomposition: AB → A + B. Single displacement: A + BC → AC + B, where a more active element replaces a less active one. Double displacement: AB + CD → AD + CB, where two ionic compounds swap partners. Combustion: a hydrocarbon burns in oxygen to make CO₂ and H₂O.
Double displacement subtypes
A double displacement reaction is driven by something leaving the solution. Precipitation forms an insoluble solid, acid–base neutralization forms water, and gas-forming reactions release a gas such as CO₂. If all the products stay dissolved, no reaction really occurs.
Redox reactions
In an oxidation–reduction reaction, electrons move from one substance to another. The element whose oxidation number goes up is oxidized (loses electrons); the one whose number goes down is reduced (gains electrons). The substance containing the reduced element is the oxidizing agent, and the one containing the oxidized element is the reducing agent. Remember OIL RIG: oxidation is loss, reduction is gain.
More than one type
Many reactions fit more than one category. Every single displacement and combustion reaction is also a redox reaction, and so is any synthesis or decomposition involving a free element.