Final answer:
The mass of the products in the reaction C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O equals the mass of the reactants because they consist of the same a. atoms, adhering to the law of conservation of mass.
Step-by-step explanation:
The mass of the products of the reaction C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O equals the mass of the reactants because the products are made up of the same a. atoms as the reactants.
This principle is based on the law of conservation of mass, which states that mass is neither created nor destroyed in a chemical reaction.
Therefore, if the reaction is properly balanced, the total mass of reactants will always be equal to the total mass of products.
When balancing a chemical equation, we ensure that the number of atoms of each element is the same on both sides of the equation.
Because the number of atoms of each element is preserved during the chemical reaction, and atoms have fixed masses, this guarantees that the total mass will remain constant.
This aligns with the relationship between moles, molar mass, and Avogadro's number, which allows for the conversion between mass and quantities of atoms or molecules.