Hydration of Cyclohexene

Lauryn Tonou

Date: 04/13/2015

Partner’s name:  Dolly, Starr

Hydration of cyclohexene

Purpose:

The purpose of this lab is to converse cyclohexene to cyclohexanol by hydration.

Introduction:

In this lab, the synthesis of cyclohexene from cyclohexanol will be performed by the dehydration of an alcohol. This is an elimination reaction, in which two groups, or atoms, will be removed from the starting molecule. Elimination reactions can occur as either a one-step (E2) or a two-step (E1) mechanism. Due to steric hindrance, this reaction will proceed primarily via E1. The synthesis of cyclohexene occurs via the following E1 elimination reaction.

[pic 1]

Materials:

• Sulfuric Acid
• Water
• Round bottom flask
• Distillation adaptor
• Condenser set
• Heater
• Sodium chloride
• Separatory funnel
• Sodium sulfate
• Container
• Acetone
• Etc…

Procedure:

Carefully add 5 mL (0.063 mole) of concentrated sulfuric acid to 1.0 mL (1.0 g, 0.056 mole) of water in a 100 mL round bottom flask fitted with a ground glass stopper.  Cool the solution to room temperature and add 5.0 mL (4.1 g, 0.049 mole) of cyclohexene.  Stopper the flask and shake until a clear homogeneous solution is formed. Allow the reaction mixture to remain at room temperature for one (1) week before proceeding.

Add 50 mL of water to the 100 mL round bottom flask.  Fit the round bottom flask with a distillation adaptor and condenser set for distillation.  Heat the mixture to hydrolyze the intermediate and distill until 25-30 mL of distillate has been collected.

Saturate the distillate with sodium chloride, separate the layers with a separatory funnel, dry the smaller (organic) layer with a small amount of sodium sulfate, and filter into a clean pre-weighed container. Reweigh the container to determine the yield and obtain an infrared spectrum (IR) of the product. Prepare a gas chromatography (GC) sample by adding 1 drop of product into a small vial and filling the vial to the neck with acetone. Submit the sample for GC analysis.

Data:

• Empty vial = 12.938 g
• Vial with final product = 14.129 g

• Final Product obtained = 14.129g - 12.938g = 1.191g

• Density of cyclohexene = 0.811 g/ml
• MW cyclohexene = 82.1 g/mol
• MW cyclohexanol = 100.2 g/mol

• Mole of cyclohexene = 4.1/82.1 = 0.0499 mol

From the equation, and even by simply looking at pictures of the structures, 1 mole of cyclohexene produces 1 mole of cyclohexanol.