Question

often conducted at reflux? What would be the result of reaction in a round-bottom flask or Erlenmeyer flask with- 1. Define the term "reflux." 2. Why are reactions often conducted at reflux simply boiling this reaction in a round-bottom flask out a reflux condenser? 3. Why must the n-butyl acetate product be rigorously dried prior to in analyor the role of the sodium iodide in today's experiment? Why is only a tiny amount needed? 5. Propose mechanisms for the formation of two possible by-products of to- day's reaction-1-iodobutane and 1-butene. 6. List three possible safety risks specific to this experiment. Briefly describe precautions to address these risks. 7. If you had conducted today's experiment using (R) 2-bromobutane, what would be the stereochemistry of the product? How, if at all, would the stereo- chemistry of the product differ if the sodium iodide had not been included in the reaction mixture?

Answer 1

Reflux is basically in simple language is heating reaction mixture with solvent and letting a soilvent boil and then vapours of solvent will go through various cycles of condensation and come back in mixture . This is done to maintain temperature and concentration of reaction mixture .

For example if our reaction mixture requires 80^oC temperature and temperature in vessel rises upto 100 ^oC so now the solvent will partially evaporate and if we have connected condensor to it , then it will pass through condensor , will get cooled and drip back into reaction vessel . So this maintained concentration through whole process and no loss of reactanct as well as products is observed.

Main purpose of reflux is to heat a solution in a controlled manner and at a constant temperature .

Reflux is done by simply connecting our reaction flask / vessel to a condensor in which water flows in outer layer and in inner layer solvent evaporates and then cools and drip back into reaction . To identify reflux is going on or not , we can look at reflux ring along the walls of round bottom flask or reaction flask . There will be droplets of solvent along walls in form of ring so that is called as Reflux ring .

If a reaction is going on and we do not use reflux condensor , then reaction might proceed to higher temperature and solvent will get fully evaporated and as a result we will get loss of reactants as well as products. So that will not be a conveinient method for reaction . In other words simply evaporation will takes place and there will be only loss because there is no control over heat , temperature that is required for reaction to occur.