The yield of benzocaine obtained from the preparation using p-aminobenzoic acid and ethanol depends on the specific reaction conditions, such as temperature, concentration, and the presence of a catalyst. The reaction between p-aminobenzoic acid and ethanol is an esterification reaction, which typically involves the use of a catalyst like sulfuric acid H2SO4 or hydrochloric acid HCl .In general, the yield of benzocaine can vary from 60% to 90% depending on the reaction conditions. To determine the exact yield, you would need to perform the reaction and measure the amount of benzocaine produced compared to the theoretical maximum.As for the effect of temperature on the yield, esterification reactions are generally equilibrium reactions, meaning that the reaction can proceed in both the forward ester formation and reverse ester hydrolysis directions. Increasing the temperature can increase the rate of both the forward and reverse reactions. However, since esterification reactions are typically exothermic releasing heat , increasing the temperature may actually shift the equilibrium towards the reverse reaction ester hydrolysis , leading to a lower yield of benzocaine.That being said, the optimal temperature for the reaction will depend on the specific reaction conditions and the presence of a catalyst. In some cases, increasing the temperature may be necessary to overcome the activation energy barrier and increase the reaction rate, even if it results in a slightly lower yield. It is essential to find a balance between reaction rate and yield to optimize the reaction conditions for benzocaine synthesis.