Question

what are the possible Sources of error in the Preparation of cyclohexene from cyclohexanol experiment?

Answer 1

Alcohols undergo elimination reaction in the presence of a strong acid to form an alkene. Strong acids such as Sulfuric acid (H₂SO₄₎ and Phosphoric acid (H₃PO₄) are used in the dehydration reaction of alcohols. The acid needs to protonate the –OH group because -OH is a strong base making it a poor leaving group. Once the –OH has been protonated to H20, it can leave and the nucleophile will obstruct a beta hydrogen to form a carbon double bond or an alkene

The synthesis of cyclohexene from cyclohexanol is an example of elimination reaction. Cyclohexanol, a secondary unsaturated alcohol, undergoes dehydration reaction to form a good leaving group which is H₂0 because the OH group of an alcohol is a very strong base making it a poor leaving group. The reaction will then be followed by the obstruction of a hydrogen atom to form a carbon double bond or an alkene which in this case is cyclohexene. Cyclohexene is an unsaturated hydrocarbon which is very reactive due to its negative center.  Synthesis was done via simple distillation since distillation gives a relatively pure yield

Phosphoric acid was added to cyclohexanol in a round bottomed flask to have the dehydration reaction which would yield to the cyclohexene. The distillate product is cyclohexene which is unsaturated and has the boiling point of 83 celcius. Synthesis was done via distillation since it helps in obtaining purer substances