Consider the reaction between sulfur trioxide and water: $$ \mathrm{SO}_{3}(g)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{H}_{2} \mathrm{SO}_{4}(a q) $$ A chemist allows \(61.5 \mathrm{~g}\) of \(\mathrm{SO}_{3}\) and \(11.2 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O}\) to react. When the reaction is finished, the chemist collects \(54.9 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4}\). Determine the limiting reactant, theoretical yield, and percent yield for the reaction.

Stoichiometry is a branch of chemistry that deals with the quantitative relationships between the amounts of reactants and products in a chemical reaction. It is based on the conservation of mass and the concept that atoms are neither created nor destroyed during a chemical reaction.

To perform stoichiometric calculations, it is essential to understand and use the mole concept, which provides a way to count atoms, ions, and molecules in bulk amounts by weighing them. Once the number of moles is known for each reactant, their ratio can be compared to the stoichiometric ratio given by the balanced chemical equation. This allows us to determine which reactant will run out first and thus is the limiting reactant.

The percent yield is a measure of the efficiency of a chemical reaction. To find the percent yield, we compare the actual yield—the amount of product actually obtained from the reaction—to the theoretical yield—the calculated amount of product that should have been obtained if the reaction had gone perfectly with 100% efficiency.

The formula for percent yield is:
\[\text{Percent Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\%\]
This calculation is a crucial step in determining the success of a chemical synthesis and enables chemists to identify and improve reaction conditions.

The theoretical yield is the predicted amount of product generated in a chemical reaction, assuming it goes to completion with no side reactions and 100% efficiency. To calculate the theoretical yield, one must consider the balanced chemical equation and the limiting reactant, which is the reactant that will be completely consumed first.

The theoretical yield serves as a reference to which the actual yield can be compared. It is a key indicator for evaluating the percentage of a reaction's successful conversion of reactants into the desired product. Understanding how to accurately calculate this yield is fundamental in both academic and industrial chemical labs.

Molar mass is a physical property of substances that is crucial for stoichiometric calculations in chemistry. It is defined as the mass in grams of one mole of the substance. One mole of any substance contains Avogadro's number of particles, which is approximately \(6.022 \times 10^{23}\).

The molar mass of a compound can be determined by summing the atomic masses of each element present in one molecule of the compound, as found on the periodic table. For instance, to find the molar mass of \(\mathrm{SO}_{3}\), one would multiply the atomic mass of sulfur by one (since there's one sulfur atom) and the atomic mass of oxygen by three (since there are three oxygen atoms), and then add the results together. Accurate calculation of molar mass is essential for converting between mass and moles, which is the foundational step in performing stoichiometric computations.