West Irondequoit Central School District

Technology Rich Lesson Plan

Name:

Patricia Koch

Grade(s)

AP Chemistry – grades 11-12

Information about the Lesson 

Title:

Beers Law Lab

Brief Description:

This website instructs the advanced chemistry student about Beers Law and then allows the student to collect and analyze data using everyday items.

Subject(s) 
integration

(time required to complete lesson, e.g. "two 45-minute sessions")

Two 45 minute periods or completely independently outside of the normal lab setting.

Goals:
(curriculum and unit related; National or State standards)

To instruct concepts related to Beers law, and run one of the suggested AP labs without use of a spectrophotometer.

Objectives:
(measurable specific activities conducted by students)

The student will determine concentration of food coloring in commercial products using two colorimetric analysis techniques, the standard series method and the balancing method.

The student will construct a Beers Law Plot based on Absorbance and Concentration of standard solutions.

The student will use Beers Law Plot as a calibration curve to determine the concentration of the dye in their sample.

Teacher Materials/Resources:
(specific materials the teacher must have to conduct the lesson, e.g. Romeo and Juliet (video), American flag, etc.)

xNone needed
or list necessary materials:

Student Materials/Resources:
(specific materials the students must have to complete the lesson, e.g. calculators, construction paper, finger paints, etc.)

None needed
or list necessary materials:
blue and yellow food coloring

Small plastic cups

Measuring spoons and cups

6 salt shakers or small jars

4 samples of commercial products containing blue or yellow dye only, examples: mouthwash, flavor ice, gatorade

Procedures:

1. Prepare standard solutions as directed in www.uncwil.edu/chem/Courses/Reeves/OnLineLabs/beerslaw/beerslaw_exp.htm 2.Prepare data table including: identification of solution a-e, standard solution concentration,depth of standard solution, depth of unknown solution, unknown concentration, and concentration in original product 3. Use standard series method to identify approximate concentration of unknowns as described in website 4. Use balancing method to accurately determine concentration of unknown as described in website. 5. Prepare a Beers Law Plot for the blue and yellow dye standards

Assessment:

The laboratory report will be graded, with emphasis on accuracy of the Beers Law Plot, data table and data collection, and mathematical calculation of concentration using the Beer-Lambert Law.

Useful Internet Resources:

http://www.uncwil.edu/chem/Courses/Reeves/OnLineLabs/beerslaw/index.htm

Other References:

Special Comments:

One of the strongly recommended AP labs is a Beers Law lab to study the relationship between the absorbance of light and the concentration of a solution, however our school does not have the spectrophotometer needed to collect the data in the routine manner. This lab provides the instruction the students need with a lab that can be completed even at home, with little or no normal chemistry equipment.

Attach a File: (link to accompanying files)