Answer:
The theoretical yield of aspirin is 3.95 grams
Explanation:
Step 1: Data given
Mass of salicylic acid = 3.03 grams
Volume of acetic anhydride = 3.61 mL
Density of acetic anhydride = 1.08 g/cm³
Step 2: The balanced equation
C4H6O3+C7H6O3→C9H8O4+C2H4O2
Step 3: Calculate moles salicylic acid
Moles salicylic acid = mass salicylic acid / molar mass salicylic acid
Moles salicylic acid = 3.03 grams /138.121 g/mol
Moles salicylic acid = 0.0219 moles
Step 4: Calculate mass acetic anhydride
Mass acetic anhydride = volume * density
Mass acetic anhydride = 3.61 mL * 1.08 g/mL
Mass acetic anhydride = 3.90 grams
Step 5: Calculate moles acetic anhydride
Moles acetic anhydride = 3.90 grams / 102.09 g/mol
Moles acetic anhydride = 0.0382 moles
Step 6: Calculate limiting reactant
For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin
Salicylic acid is the limiting reactant. It will completely be consumed. (0.0219 moles). Acetic anhydride is in excess. There will react 0.0219 moles. There remain 0.0382 - 0.0219 =0.0163 moles
Step 7: Calculate moles aspirin
For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin
For 0.0219 moles salicylic acid we'll have 0.0219 moles aspirin
Step 8: Calculate theoretical yield of aspirin
Mass of aspirin = moles aspirin *molar mass aspirin
Mass of aspirin = 0.0219 moles *180.15 g/mol
Mass of aspirin = 3.95 grams
The theoretical yield of aspirin is 3.95 grams
