Final answer:
To write a chemical reaction equation, identify the reactants and the products and their chemical formulas.
Step-by-step explanation:
To write the reaction equation for a chemical reaction, you first need to identify the reactants and the products. The reactants are the substances consumed in the reaction, and the products are those that are formed. A reaction equation must state the correct chemical formulas for each reactant and product, and it must be balanced, with the same number of each type of atom on both sides of the equation.
For example, the combustion of methane gas can be represented by the balanced chemical equation:
In this reaction, CH4 (methane) and O2 (oxygen) are the reactants and CO2 (carbon dioxide) and H2O (water) are the products. To calculate the quantities produced or consumed, stoichiometry is used, which involves the molar ratios of reactants and products indicated by the coefficients in the balanced equation.
Write the reactants on the left side of the equation and the products on the right, and balance the equation to ensure that the number of atoms for each element is the same on both sides.