Final answer:
To find the limiting reagent and the mass of product formed in a chemical reaction, one must use stoichiometry and the balanced chemical equation to compare the mole ratio of reactants. The reactant that restricts product formation is the limiting reagent, and its mole quantity determines the theoretical yield and leftover excess reagent mass.
Step-by-step explanation:
In answering the question about limiting reagents, the first step is to identify which reactant will be exhausted first in a chemical reaction, which in turn will dictate the amount of product that can be produced. Generally, stoichiometry helps us determine this by using the mole ratio from the balanced chemical equation. Once the limiting reagent is identified, the theoretical yield can be calculated. For example, with a molar mass of 197.84 g/mol for As2O3, if 0.334 mol is produced, the mass would be 66.1 g. This product mass is found by multiplying the moles by the molar mass.
If copper sulfate is the limiting reactant, the excess reactant will be left over after the reaction. These quantities can be determined through mass-mass calculations. It is important to convert all reactant masses to moles to accurately ascertain the limiting reagent. The mass of any excess reagent remaining can be found by taking the initial mass of the reagent and subtracting the mass that reacted, which is based on the mole ratio and the amount consumed by the limiting reagent.