Why do you have a certain number of reactants on the left side? Use the example below to support your answer.
In a chemical reaction, the number of reactants on the left side is determined by the stoichiometry of the reaction. This means that the number of moles of each reactant is carefully balanced so that they react in the proper ratios according to the chemical equation.
For example, consider the reaction:
2H2 + O2 -> 2H2O
In this reaction, two molecules of hydrogen gas (H2) react with one molecule of oxygen gas (O2) to produce two molecules of water (H2O). The numbers in front of the reactants and products indicate the stoichiometry of the reaction, showing the ratio in which the substances combine.
Having a specific number of reactants ensures that the reaction proceeds efficiently and according to the balanced equation, with no leftover or wasted reactants. It also helps chemists predict the amount of products that will be formed in the reaction.