Vernier Software and Technology
Vernier Software & Technology

Determination of a Boiling Point


The boiling point of a substance is a useful physical property for the characterization of pure compounds. A common method for the determination of boiling points as well as separating and purifying volatile liquids, is distillation, which makes use of the specific boiling points, of the liquid components in the mixture. When there is only one volatile compound, or when one of the liquids has a boiling point well below the others, a simple distillation is used. However, if there are two or more liquid components, which have boiling points near each other, a fractional distillation must be used.

Using simple distillation, you will separate toluene from a non-volatile dye. Then, using a fractional distillation apparatus, you will separate toluene and cyclohexane. While performing the distillation, you will monitor the temperature that the volatile liquid has, in the gas phase, using the Vernier Wide-Range Temperature Probe. This temperature should remain constant as each distillate is being condensed, and actually represents the boiling point of this chemical. To confirm the presence of each compound, you will measure the density of your distillates.


In this experiment, you will

  • Assemble and perform a simple distillation of toluene.
  • Assemble and perform a fractional distillation to isolate toluene and cyclohexane.
  • Produce a graph of time vs. temperature for each distillation.
  • Determine the density of each purified compound.
  • Identify an unknown compound based on boiling point and density.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Organic Chemistry with Vernier

See other experiments from the lab book.

1Determining Melting Temperature
3Determination of a Boiling Point
4Identifying an Unknown Analgesic by Three Methods
5Separation of Organic Compounds by Acid-Base Extraction Techniques
6Understanding Polarimetry
7Identification of Organic Unknowns Using Polarimetry
8Investigating Gas Chromatography
9Fractional Distillation of Esters
10Understanding Intermolecular Forces Using a Gas Chromatograph: Enthalpy of Vaporization
11Investigating Thermodynamic Relationships of Substituted Hydrocarbons
12Extraction of Spinach Pigments and Analysis by Electronic Absorption Spectroscopy
13SN1: Synthesis of t-butyl chloride
14SN2: Synthesis of 1-bromobutane
15Observing the Reaction Kinetics of Sucrose with Polarimetry
16The Synthesis and Analysis of Aspirin
17Isolation of R-(+)-Limonene from Oranges using Steam Distillation
18Synthesizing Ethyl Acetate by Fisher Esterification
19Synthesis of Dibenzalacetone by Aldol Condensation
20The Diels-Alder Reaction of Anthracene with Maleic Anhydride
21Friedel-Crafts Acylation of Ferrocene
22Grignard Formation of Crystal Violet
23Synthesis of Fluorescein
24Synthesis of Methyl Orange and Its Application to Textiles
25Analysis of Natural Products
26Using a Gas Chromatograph: Identifying an Unknown Compound

Experiment 03 from Organic Chemistry with Vernier Lab Book

<i>Organic Chemistry with Vernier</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

Go to top