Titration Curves: An Application of the Logistic Function
Recommended for grades 9–12.
Introduction
Think about how a cold would spread through your school. If one person is infected, that student may infect other students. The cold may spread slowly at first. Then, as more students have the cold and are spreading it, growth is more rapid. Eventually the spread of the cold will slow down because most people will have had it and there will be no others to infect. The maximum number of students in the school who can contract the cold is the number of students in the school.
A logistic function is often used to model this type of situation. The logistic function is an exponential function at heart, but a ratio and offset make its behavior more interesting.
In this activity, you will add base to an acid and use a logistic function to model the data and locate the equivalence point.
Objectives
- Record pH vs. base volume data for an acid-base titration.
- Manually model the titration curve using a logistic function.
- Describe the role of each parameter in the logistic function.
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?
Standards Correlations
See all standards correlations for Real-World Math with Computers »
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.