Reactant

What Does Reactant Mean?

A reactant is one or more starting chemicals that molecularly interact with each other to form a new product. In the chemical reaction between iron and water that forms rust, iron and water are both reactants and rust (iron oxide) is the product.

Corrosionpedia Explains Reactant

A typical reaction may be given by an equation of the form:

A + B → C

In this equation A and B are reactants and C is the product. However, there does not necessarily have to be multiple reactants in a reaction. In a decomposition reaction, such as:

C → A + B

C is the reactant, while A and B are the products.

By convention, reactants are always positioned on the left side of the arrow while products are on the right.

A typical corrosion reaction is:

2Fe(s) + O₂(g) + 2H₂O(1) → 2Fe²⁺(aq) + 4OH-(aq)