Aspirin, \(\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4}\), is prepared by reacting salicylic acid, \(\mathrm{C}_{7} \mathrm{H}_{6} \mathrm{O}_{3}\), with acetic anhydride, \(\mathrm{C}_{4} \mathrm{H}_{6} \mathrm{O}_{3}\), in the reaction $$ \mathrm{C}_{7} \mathrm{H}_{6} \mathrm{O}_{3}(s)+\mathrm{C}_{4} \mathrm{H}_{6} \mathrm{O}_{3}(l) \longrightarrow \mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4}(s)+\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}(l) $$

The given chemical equation is already balanced; it has the same number of each type of atom on both sides. Therefore, no changes are needed.

To find the number of moles of each substance, use the given mass and the molar mass. Let's assume we have x grams of salicylic acid and y grams of acetic anhydride. The molar masses of each substance are: - Salicylic acid: 138.12g/mol - Acetic anhydride: 102.09g/mol - Aspirin: 180.16g/mol - Acetic acid: 60.05g/mol So, the number of moles of each reactant can be determined using the formula n = mass / molar mass: - moles of salicylic acid = x / 138.12 - moles of acetic anhydride = y / 102.09

Since we know the number of moles of each reactant and the balanced chemical equation, we can find the number of moles of the products formed: - moles of aspirin = moles of salicylic acid = x / 138.12 - moles of acetic acid = moles of acetic anhydride = y / 102.09 Now we can find the mass of each product using the molar mass: - mass of aspirin = moles of aspirin * molar mass of aspirin = (x / 138.12) * 180.16 - mass of acetic acid = moles of acetic acid * molar mass of acetic acid = (y / 102.09) * 60.05

To determine the limiting reactant, compare the mole ratio of the reactants. The balanced equation tells us that one mole of salicylic acid reacts with one mole of acetic anhydride. If the mole ratio of salicylic acid to acetic anhydride is greater than 1:1, salicylic acid is in excess and acetic anhydride is the limiting reactant. If the ratio is less than 1:1, acetic anhydride is in excess and salicylic acid is the limiting reactant. If the ratio is exactly 1:1, both reactants are fully consumed in the reaction. Based on the limiting reactant, calculate the theoretical yield of aspirin: - If salicylic acid is the limiting reactant, the theoretical yield of aspirin = mass of aspirin from salicylic acid = (x / 138.12) * 180.16 - If acetic anhydride is the limiting reactant, the theoretical yield of aspirin = mass of aspirin from acetic anhydride = (y / 102.09) * 180.16