In chemistry, a product is a substance that is formed as the result of a chemical reaction. In a reaction, starting materials called reactants interact with each other. After passing through a high energy transition state (achieving the activation energy for a reaction), the chemical bonds between the reactants are broken and rearranged to yield one or more products.
Products in Chemical Equations
When a chemical equation is written, reactants are listed on the left side, followed by the reaction arrow, and finally by-products. Products are always written on the right side of a reaction, even if it is reversible.
A + B → C + D
Where A and B are reactants and C and D are products.
In a chemical reaction, atoms are rearranged, but not created or destroyed. The number and type of atoms on the reactants side of the equation are the same as the number and type of atoms in the products.
Chemical vs. Physical Change
The formation of products that are different from reactants is the difference between a chemical change and a physical change of matter. In a chemical change, the formulas of at least one of the reactants and products are different. For example, the physical change in which water melts into a liquid may be represented by the equation:
H2O(s) → H2O(l)
The chemical formulas of the reactants and products are the same.
Examples of Products
Silver chloride, AgCl (s), is the product of the reaction between the silver cation and chloride anion in aqueous solution:
Ag+ (aq) + Cl- (aq) → AgCl (s)
Nitrogen gas and hydrogen gas are the reactants that react to form ammonia as a product:
N 2 + 3H 2 → 2NH 3
The oxidation of propane yields the products carbon dioxide and water:
C3H8 + 5 O2 → 3 CO2 + 4 H2O