Question

A student adds 207.6 grams of C7H6O3 to an excess of C4H6O3, this produces C9H8O4 and C2H4O2. Calculate the percent yield if 231 grams of aspirin (C9H8O4) is produced

Answer 1

C₇H₆O₃ + C₄H₆O₃ = C₉H₈O₄ + C₂H₄O₂

m_theoretical (C₉H₈O₄) = m(C₇H₆O₃ ) × Mr(C₉H₈O₄ ) / Mr(C₇H₆O₃) = 207.6 g × 180 g/mol / 138 g/mol = 270.8 g

%w = (m_actual / m_theoretical) × 100 % = (231 g / 270.8 g) × 100 % = 85.3 %

Answer: 85.3 %