The maximum yield of benzocaine from the reaction of p-aminobenzoic acid and ethanol depends on the stoichiometry of the reaction, the purity of the reactants, and the reaction conditions such as temperature, pressure, and catalyst presence. The reaction can be represented as follows:p-aminobenzoic acid + ethanol benzocaine + waterIn an ideal scenario, assuming 100% conversion and no side reactions, the maximum yield of benzocaine would be determined by the stoichiometry of the reaction, which is 1:1. This means that one mole of p-aminobenzoic acid reacts with one mole of ethanol to produce one mole of benzocaine.Reactant ratios: To achieve the maximum yield, the reactants should be present in stoichiometric amounts. If one of the reactants is present in excess, it will not contribute to the formation of more product and may lead to side reactions or increased waste. Therefore, maintaining a 1:1 molar ratio of p-aminobenzoic acid to ethanol is important for maximizing the yield of benzocaine.Reaction temperature: The reaction temperature can also affect the yield of benzocaine. Higher temperatures can increase the reaction rate, leading to faster product formation. However, excessively high temperatures may cause side reactions or decomposition of the reactants or product, leading to a decrease in yield. The optimal temperature for this reaction is typically around 80-100C, as it provides a good balance between reaction rate and stability of the reactants and product.In summary, the maximum yield of benzocaine from the reaction of p-aminobenzoic acid and ethanol can be achieved by maintaining a 1:1 molar ratio of the reactants and controlling the reaction temperature to avoid side reactions or decomposition. Other factors, such as the presence of a catalyst or the purity of the reactants, can also influence the yield. However, it is important to note that achieving a 100% yield is often not possible in practice due to various factors such as side reactions, reactant impurities, and product losses during purification.