Question

19 if all of the reactants in a chemical equation are completely used, which of the following statements accurately describes the relationship between the reactants and the products? (1 point) the reactants must contain more complex molecules than the products do. the products must have a different physical state than the reactants. the density of the reactants must equal the density of the products. the total mass of the reactants must equal the total mass of the products.

Explanation:

According to the law of conservation of mass in a chemical reaction, when all reactants are completely used, the total mass of reactants equals the total mass of products. The complexity of molecules (reactants vs products) isn't necessarily related to complete usage. Physical state change (reactants vs products) is not a requirement for complete reactant usage. Density equality (reactants vs products) is not a consequence of complete reactant consumption.

Answer:

The total mass of the reactants must equal the total mass of the products.