Question

What mass should be used to calculate the theoretical yield for this reaction when exactly 93 mg of ferrocene and 0.35 mL of acetic anhydride is used?

The following information will be helpful to find the answer to this question:
Ferrocene molar mass:186.04 g/mol
Acetic Anhydride molar mass:102.09 g/mol
Acetic Anhydride density: 1.08 g/mL

a. ferrocene because it is the limiting reagent.
b. ferrocene because it is the reagent in excess.
c. acetic anhydride because it is the limiting reagent.
d. acetic anhydride because it is the reagent in excess.

Answer 1

To calculate the theoretical yield for this reaction, the mass of ferrocene should be used because it has fewer moles and is thus the limiting reagent. The correct answer is option a.

Step-by-step explanation:

We need to compare the mole ratio of the reactants to their stoichiometry in the balanced chemical equation. To start, we convert the mass of ferrocene to moles by dividing by its molar mass (186.04 g/mol). For 93 mg (0.093 g) of ferrocene, this gives us 0.0005 moles of ferrocene.

Next, we calculate the moles of acetic anhydride. First, we convert the volume of acetic anhydride (0.35 mL) to mass using its density (1.08 g/mL), which gives us 0.378 g of acetic anhydride. Then, we divide this mass by its molar mass (102.09 g/mol) to obtain approximately 0.0037 moles of acetic anhydride.

Without the balanced chemical equation, we cannot know the exact stoichiometry; however, typically, the substance with fewer moles is the limiting reagent. In this case, ferrocene has fewer moles than acetic anhydride, making it the limiting reagent (option a). Therefore, the mass of ferrocene should be used to calculate the theoretical yield.