Concept:Stoichiometry concerns the quantitative relationships between reactants and products in a chemical reaction, and its calculations depend on the law of conservation of mass.
Explanation:The law of conservation of mass states that matter can neither be created nor destroyed during a chemical reaction.
It means the total mass of all reactants before a reaction equals the total mass of all products formed after the reaction.
The mass of every element in the product(s) must be exactly equal to the mass of that same element in the reactant(s).
Therefore, the total mass of reactants equals the total mass of products.
Stoichiometric calculations, such as balancing equations and determining mole ratios, rely on this fundamental principle.
A balanced chemical equation always satisfies the relationship:
mass of reactants=mass of products.
It is this principle that allows chemists to predict the exact amounts of substances consumed or produced in a reaction.
Thus, stoichiometry is not based on multiple proportions, constant composition, or conservation of energy.
Its entire framework rests on the law of conservation of mass because atoms are only rearranged, never lost or gained, in a chemical reaction.
This law is also known as the law of conservation of matter.
Answer:D. conservation of mass