Aspirin can be made in the laboratory by reacting acetic anhydride (C4H6O3) with

Question

Aspirin can be made in the laboratory by reacting acetic anhydride (C4H6O3) with salicylic acid (C7H6O3) to form aspirin (C9H8O4) and acetic acid (C2H4O2). The balanced equation is
C4H6O3+C7H6O3?C9H8O4+C2H4O2
In a laboratory synthesis, a student begins with 2.90mL of acetic anhydride (density=1.08g/ml) and 1.28g of salicylic acid. Once the reaction is complete, the student collects 1.23g of aspirin.

Determine the limiting reactant for the reaction?

Determine the theoretical yield of aspirin for the reaction?

Determine the percent yield of aspirin for the reaction.

Explanation / Answer

The balanced chemical equation is
C4H6O3+C7H6O3?C9H8O4+C2H4O2

Mass of acetic anhydride = volume x density = 2.90 mL x 1.08 g/ml = 3.132 g.

Molar mass of acetic anhydride (C4H6O3) = 102 g/mol

Moles of acetic anhydride = 3.132 g / 102 g/mol = 0.031 mol

Molar mass of salicylic acid = 138 g/mol

Moles of salicylic acid = 1.28 g / 138 g/mol = 0.0093 mol

As, the moles of salicylic acid are less than the acetic anhydride, salicylic acid is the limiting reagent.

1 mol of salicylic acid produces 1 mol aspirin.

So, 0.0093 mol of salicylic acid produces 0.0093 mol aspirin.

Mass of aspirin = 0.0093 mol x 180 g/mol = 1.670 g.

Theoretical yield of aspirin = 1.670 g

percentage yield = (Practical yield / Theoretical yield) x 100

Given, practical yield = 1.23 g

% yield = (1.23 / 1.67) x 100

= 73.7 %

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.