If salicylic acid (138 u) reacts with acetic anhydride (102 u) to from aspirin (180 u) calculate % atom economy

Step-by-step solution

The atom economy is calculated as the ratio of the molecular mass of the desired product to the total molecular mass of all reactants, expressed as a percentage. Given the molecular masses: aspirin (desired product) = 180 u, salicylic acid = 138 u, and acetic anhydride = 102 u, the sum of reactant masses is 138 + 102 = 240 u. Substituting into the formula yields 180 240 100 % = 0.75 100 % = 75 % . Final answer: D