Difference Between a Chemical Reaction and the Equation

What is the difference between a chemical reaction and the chemical equation? These terms are often used interchangeably, but although theyre related, theyre different things. A chemical reaction is a process that occurs when one or more substances are changed into one or more new substances. For example: Hydrogen and oxygen gas combine to produce water.Sodium chloride (table salt) dissociates in water to form sodium and chlorine ions.Methane combusts in oxygen to form carbon dioxide, heat, and water. On the other hand, a chemical equation is the symbolic representation of a chemical reaction. Atomic symbols are used to represent the elements that take part in a reaction. The numbers represent the ratios of reactants and products that produce the reaction. Arrows point the direction a reaction occurs, with the arrow pointing from reactants to products. For example, using for the above chemical reactions: 2 H2(g) O2(g) → 2 H2O(ℓ)This chemical equation reads: Two hydrogen gas molecules and one oxygen gas molecule produce two molecules of water.NaCl(s) H2O → Na(aq) Cl-(aq)One molecule of sodium chloride dissociates in water into one sodium ion and one chlorine ion.CH4 2 O2 → CO2 2 H2O (DeltaH -891 kJ/mol)This equation shows one methane molecule and two oxygen gas molecules form a carbon dioxide molecule, two water molecules and release 891 kilojoules of heat. To review:Chemical reactions are processes in which reactants become new products.Chemical equations are the symbolic representation of chemical reactions.