Which catalyst is used in the lab experiment?

Phosphoric acid is often chosen as a catalyst in organic reactions, particularly in esterification reactions. It is a good acid catalyst that facilitates the reaction without being consumed in the process. Phosphoric acid promotes the formation of the intermediate species necessary for the reaction to occur. Its ability to both donate protons and stabilize carbocations can enhance the reaction's rate and yield. Its relatively mild nature compared to some of the other strong acids makes it particularly useful in laboratory settings where conditions need to be controlled to prevent unwanted side reactions or degradation of sensitive organic compounds. Therefore, utilizing phosphoric acid as a catalyst helps in achieving effective and efficient results in organic synthesis experiments.