Chemistry – Organic chemistry - Fuels | e-Consult

Experiment: Determining the Boiling Point of a Liquid using Fractional Distillation

Equipment Required:

• Crude oil or a liquid with a known boiling point range (e.g., a mixture of alkanes)
• Fractionating column (packed with glass beads)
• Thermometer
• Condenser
• Collecting flask
• Bunsen burner
• Stand and clamps
• Heat source (e.g., heating mantle or hot plate)
• Safety goggles
• Gloves

Procedure:

1. Set up the fractional distillation apparatus as described above, ensuring all connections are tight to prevent leaks.
2. Carefully heat the crude oil in the flask using the Bunsen burner or heating mantle.
3. Allow the vapour to rise through the fractionating column.
4. Monitor the temperature at the top of the column using the thermometer.
5. When a steady temperature is reached and a liquid begins to condense in the condenser, collect the distillate in the collecting flask.
6. Record the temperature at which the liquid begins to condense. This is the boiling point of the liquid.
7. Repeat the process for different fractions, collecting them in separate flasks and recording the temperature at which each fraction condenses.

Safety Precautions:

• Wear safety goggles and gloves at all times to protect your eyes and skin from splashes of hot liquids.
• Handle the Bunsen burner and hot plates with care to avoid burns.
• Ensure the apparatus is securely mounted to prevent it from tipping over.
• Work in a well-ventilated area to avoid inhaling harmful fumes.
• Dispose of any waste materials properly.
• Be aware of the potential for explosions if flammable vapours are present.