Final answer:
The reaction between A and B₂ follows the Law of Definite Proportions and the Law of Conservation of Mass. The correct equation that represents the stoichiometry is 2 A + B₂ → A₂B₂, where 2 atoms A react with 1 molecule B₂ to produce one molecule A₂B₂ with no excess atoms remaining.
Step-by-step explanation:
The subject question asks which equation best describes the stoichiometry of the reaction between A and B₂. In order to determine the correct stoichiometric coefficients, we need to use the information that when 1 gram of A reacts with 8 grams of B, they produce 9 grams of C, according to the Law of Definite Proportions and the Law of Conservation of Mass. This implies a straightforward, fixed ratio of substances reacting and forming products. Furthermore, stoichiometry involves counting atoms to ensure mass is conserved and that there are equal numbers of each type of atom on both sides of the reaction equation.
The correct equation must reflect the proportions of the reactants combining without any excess of reactants or deficit in the products. Based on the aforementioned laws, it is possible to deduce that the reaction between A and B₂ has a ratio that results in compound A₂B₂ without extra A or B atoms left over. Therefore, option C, which states 2 A + B₂ → A₂B₂, is the equation that best fits the given scenario, as it implies 2 atoms of A reacting with 1 molecule of B₂ (composed of 2 B atoms) to produce one molecule of A₂B₂, aligning with the mentioned laws of chemistry.