RP10 - Preparing an Organic Liquid

Aim: To synthesise and purify a sample of an organic liquid (e.g. cyclohexene from cyclohexanol).

Apparatus & Reagents:

• Round bottom flask

• Reflux condenser

• Distillation apparatus

• Separating funnel

• Measuring cylinder

• Thermometer

• Beaker

• Anti-bumping granules

• Organic reagents (e.g. cyclohexanol, )

• Drying agent (e.g. anhydrous  )

• Sodium hydrogencarbonate solution

• Water

• Ice bath

Procedure

A. Reflux (for reaction completion)

• Add the organic reactant and acid catalyst to a round bottom flask.

• Add anti-bumping granules.

• Assemble the reflux apparatus with a vertical condenser.

• Gently heat the mixture for ca. 30 minutes.

B. Distillation (isolate the product) 

• Rearrange the apparatus for distillation.

• Collect the fraction boiling near the expected boiling point of the desired compound.

C. Purification (washing & drying)

• Transfer the distillate to a separating funnel.

• Add sodium hydrogencarbonate solution to neutralise any remaining acid. (Release pressure by inverting and opening the tap.)

• Remove aqueous layer; retain organic layer.

• Wash the organic layer with water and discard the aqueous layer again.

• Add anhydrous   or     to remove water. Swirl until liquid goes from cloudy to clear.

• Decant the dry liquid into a clean, dry container.

• Redistil to obtain a pure product (collect at boiling point).