Chemical Equation - Form

Form

A chemical equation consists of the chemical formulas of the reactants (the starting substances) and the chemical formula of the products (substances formed in the chemical reaction). The two are separated by an arrow symbol (, usually read as "yields") and each individual substance's chemical formula is separated from others by a plus sign.

As an example, the formula for the burning of methane can be denoted:

CH₄+ 2 O₂ CO₂+ 2 H₂O

This equation would be read as "CH four plus two O two yields CO two and two H two O." But for equations involving complex chemicals, rather than reading the letter and its subscript, the chemical formulas are read using IUPAC nomenclature. Using IUPAC nomenclature, this equation would be read as "methane plus oxygen yields carbon dioxide and water."

This equation indicates that oxygen and CH₄ react to form H₂O and CO₂. It also indicates that two oxygen molecules are required for every methane molecule and the reaction will form two water molecules and one carbon dioxide molecule for every methane and two oxygen molecules that react. The stoichiometric coefficients (the numbers in front of the chemical formulas) result from the law of conservation of mass and the law of conservation of charge (see "Balancing Chemical Equation" section below for more information).