Why do you have a certain number of reactants on the left side? Use the example below to support your answer.
In a chemical equation, the number of reactants listed on the left side represents the specific ratio in which the substances will react with each other. This is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction, only rearranged.
For example, in the reaction 2H2 + O2 -> 2H2O, there are two molecules of hydrogen gas (H2) reacting with one molecule of oxygen gas (O2) to produce two molecules of water (H2O). This balanced equation shows the specific ratio in which the reactants must combine in order for the reaction to occur and for the mass to be conserved. If there were not a specific number of reactants listed on the left side, the equation would not accurately represent the stoichiometry of the reaction.