Observing the Reaction Kinetics of Sucrose with Polarimetry
Recommended for grades 13–16.
Introduction
Polarimeters can be used in kinetics experiments to follow the change in concentration of an optically active sample as a reaction proceeds. Sugars are common examples of optically active compounds. Sucrose is a disaccharide that can be broken down into its two substituent monosaccharides, glucose and fructose.
This process occurs too slowly in water to be monitored on any real time scale, so a catalyst, acid or enzyme, must be added to accelerate the reaction rate. In this experiment, hydrochloric acid is used to catalyze the reaction while its rate is monitored using a polarimeter. The experiment will be repeated using the enzyme invertase to catalyze the reaction.
Objectives
In this experiment, you will
- Calculate the specific rotation of sucrose using a Polarimeter.
- Observe the cleavage kinetics of sucrose with an acid catalyst, hydrochloric acid.
- Observe the cleavage kinetics of sucrose with an enzyme catalyst, invertase.
- Calculate the rate constant for each run from the rotational readings.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer and LabQuest data collection
- List of materials and equipment
The experiment preview does not include essential teacher information, safety tips, or sample data. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
No standards correlations for this experiment.
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.