Question

Reflux procedure and report 1) You start at the same time and in same devices reflux of 40 ml of hexane and in another one 40 ml of benzene. Which device will start reflux first? Explain 2) Why reflux is a referable method of running chemical reactions that require heating? Why not just heat your reaction content in the Erlenmeyer flask? 3) Why do we turn heat off first and water only after your device is at room temperature? 4) What happens if you use 100 ml of solvent instead of 50 ml? 5) If you are using Toluene as your solvent, what temperature of water bath would you need?

Answer 1

Boiling point of benzene -80 °C Since boiling point of hexane is less, it will take less time to reflux. 2) If the reaction mixture is heated in Erlenmeyer flask, the solvent will evaporate and we need to add the solvent again and again. Due to this more solvent will be used. Whereas if we reflux the mixture, the solvent will not be lost. It will be more cost-effective method and is also good for our environment. 3) We first turn off the heat. Since the reaction mixture also has entraped heat, which can help in evaporating the solvent, making the vessel dry. That is why, when no more further reaction is proceeding and the mixture come to room temperature, water is turned off. 4 More solvent will ake more time for refluxing