Question

What is the purpose of reflux for the competitive nucleophiles experiment? Be explicit. This question is referring to heating a mixture (44mL of pre-diluted sulfuric acid, 4.75 g ammonium chloride, 8.75 g ammonium bromide, and 2.5 mL of 1-butanol) under reflux for 75 minutes at a gentle boil.

Answer 1

The purpose of reflux for the Competitive nucleophiles experiment:

When 2.5ml of 1-Butanol is heated with a mixture of 44ml H₂SO₄ , 4.75g NH₄Cl , 8.75g NH₄Br the nucleophilic substitution

reaction takes place.

This reaction follows SN₂ mechanism and therefore the rate of the reaction is dependant on both reactant and nucleophile.

The reason reflux is that in this reaction two Nucleophiles are present namely Cl^- and Br^-.

Since two nucleophiles are present competitive nucleophilic substitution takes place and two products are obtained

Chloro substituted and Bromo substituted products.

Among these nucleophile Br^- is said to be strong nucleophile and more number of Br^- are present as the concentration of NH₄Br is more.

To get this as a major product the reaction is refluxed for 75minutes.