Acetic acid reacts with excess ethanol in the presence of concentrated H₂SO₄ to give ethyl acetate (Fischer esterification). If 5.0 g of acetic acid are used, calculate the theoretical mass of ethyl acetate obtained. (Molar masses: CH₃COOH = 60.05 g mol⁻¹, CH₃COOC₂H₅ = 88.11 g mol⁻¹).
Answer
7.34 g ethyl acetate
The correct answer is 7.34 g ethyl acetate — Therefore, the theoretical yield is 7.34 g of ethyl acetate.
Step-by-step solution
- Write the balanced equation: CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O.
- Determine moles of acetic acid: n = mass / molar mass = 5.0 g / 60.05 g mol⁻¹ = 0.0833 mol.
- The reaction stoichiometry is 1:1, so the maximum moles of ethyl acetate formed = 0.0833 mol.
- Calculate the mass of ethyl acetate: mass = n × molar mass = 0.0833 mol × 88.11 g mol⁻¹ = 7.34 g.
- Therefore, the theoretical yield is 7.34 g of ethyl acetate.
Common mistake: Forgetting that one mole of water is also produced, leading to an incorrect mole ratio.
Concept tested: Fischer esterification and stoichiometry
Published · How this solution was prepared and checked
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