Vernier Software and Technology
Vernier Software & Technology

Separating Molecules


In this investigation, you will be given an aqueous mixture of two or more substances, all of which are FD&C food dyes. Your objectives will be to identify and separate the food dyes in the mixture, using two laboratory techniques.


The first objective is to try to identify the food dyes in the mixture, using absorbance spectroscopy. The absorbance spectrum of a solution of each food dye is a unique property of the substance. By carefully examining the absorbance spectra, you should be able to identify one or more of the food dyes.

The second objective is to separate the food dyes using chromatography. Chromatography is a name for a family of methods used to separate mixtures into their individual components. The method is based on the affinity that molecules have for other molecules, also known as intermolecular forces of attraction. You will use paper chromatography to separate the food dyes in your mixture.

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?

Vernier Chemistry Investigations for Use with AP* Chemistry

See other experiments from the lab book.

1Investigating Food Dyes in Sports Beverages
2Determining the Copper Content in Brass
3Investigating Water Hardness
4The Acidity of Juice and Soft Drinks
5Separating Molecules
6Identifying an Unknown Substance
7Investigating the Purity of a Mixture
8Determining the Percent Peroxide in a Commercial Product
9Investigating the Components of a Commercial Tablet
10The Effect of Acid Rain on a Marble Structure
11Investigating the Kinetics of a Crystal Violet Reaction
12Investigating Commercial Hand Warmers
13Investigating LeChatelier’s Principle
14Investigating Acid-Base Titrations
15The Buffering Ability of Commercial Products
16Testing the Effectiveness of a Buffer

Experiment 5 from Vernier Chemistry Investigations for Use with AP* Chemistry Lab Book

<i>Vernier Chemistry Investigations for Use with AP* Chemistry</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.

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