Chemistry Lesson Plan - Technology-Connected Lesson Plan

Document Sample
Chemistry Lesson Plan - Technology-Connected Lesson Plan Powered By Docstoc
                              Technology-Connected Lesson Plan
                               By Gayle Crane, Chemistry and
                                 Sharon Lantz, Technology
                 Modified from Lab developed by Don Miller and Gordon Parker
                              at University of Michigan - Dearborn.

Lesson Title: Plop, plop, fizz, fizz – Let’s see how much relief there is!
(Determination of the amount of a chemical substance)

Grade level: 9-12

Curriculum Areas
 Math
 Science
 Technology

Objectives of Lesson
 understand the concepts of neutralization
 become familiar with the technique of titration

Colorado Content Standards:
             Students make measurements
             Students construct data tables of observations and measurements.
             Students practice the scientific method.
             Students identify sources of error in an experiment.
             2.3 Students observe and measure physical interactions of matter.
             Students learn about refining a hypothesis based on an accumulation of
              data over time.
Technology Standards:
            o Students use technology tools to enhance learning, increase productivity,
              and promote creativity.
            o Students use productivity tools to collaborate in constructing technology-
              enhanced models, prepare publications, and produce other creative works.
            o Students use technology to locate, evaluate, and collect information from
              a variety of sources.
            o Students use technology tools to process data and report results.
            o Students use technology resources for solving problems and making
              informed decisions
Red Rocks Community College
 Tums, Rolaids, Milk of Magnesia
 Mortar and Pestle
 Weighing boats
 methyl orange solution
 hydrochloric acid
 Sheets of white paper
 Burets
 3 125-mL Erlenmeyer flasks
 Funnels
 Handouts
           o Plop Table
           o Calculations/Question Sheet
           o “Acids and Bases” information sheet
           o Acid/Base Properties of Household Chemicals worksheet

Technology Connection:
 Computers
 Printer
 Projection Device
 Publisher
 Digital Camera
 Excel
 Internet

Teacher Background:
In this lab, we will analyze the effectiveness of common preparations such as TUMS,
Rolaids, and Milk of Magnesia in neutralizing the excess hydrochloric acid in your
stomach. We will determine which product has the greatest acid neutralizing power per
unit of cost.
The active ingredient in an antacid is a base. A base is the opposite of an acid. When
brought into contact with an acid both lose their characteristic properties, i.e. they are
neutralized. The common bases used in antactid tablets are aluminum hydroxide
(Al(OH)3), magnesium hydroxide (Mg(OH)2, calcium hydroxide (Ca(OH)2 or some
combination of these. Although each will neutralize stomach acid, excessive use is not
recommended. Aluminum hydroxide can cause constipation, magnesium hydroxide also
functions as a laxative, and calcium hydroxide can stimulate extra acid production in the
stomach to replace that which has been neutralized.

Each of these antacids contains a chemical which reacts with the acid in your stomach,
neutralizing it and reducing the excess acidity. We will add acid to the material of these
preparations, and by measuring the amount of acid which is neutralized by the prescribed
dosage, compare their capacities for acid neutralization. The chemical technique of
neutralizing a chemical with a measured quantity of another chemical is known as
titration. Your instructor will explain the concepts of titration, pH and indicators and will
demonstrate the techniques involved. Then, you can carry out the procedures for the

Red Rocks Community College
antacid preparation assigned to your group. We will compare results after you have
finished. Take care to carry out your measurements with precision.

Lesson Procedures:
In the Classroom:
 Before the lab section of the lesson, the teacher should give a presentation on Acids
    and Bases. Teacher can refer to the “Acids and Bases” information sheet.
 Pass our the Acid/Base Properties of Household Chemicals worksheet and Blue and
    Red Litmus paper for students to take home and test different substances.

Investigation Part I (In the Chemistry Lab)
 Divide into Groups; Assign one person in the group the job of taking digital pictures
   of each step. (rotate this job)
1. Determine the mass of the recommended dosage of the antacid using the balance.

        name of antacid_______________________

        mass of prescribed dosage_______________grams (1)

   Record this value in the plop table.

2. Make a solution of the antacid in water. First, grind the antacid using a mortar and
pestle until only a fine powder remains. Carefully measure 100 mL of distilled water in a
graduated cylinder. Wash the antacid powder from the mortar and pestle into a 250 mL
flask with the 100 mL of water. You should now have a uniform slurry with no chunks
of antacid in the solution. Be sure to get all of the antacid from the mortar and pestle
with a small amount of distilled water from a wash bottle.

3. Add 10 drops of methyl orange solution to the flask. Methyl orange is a pH indicator
which is a yellow color in basic solutions (here pH greater than 4.4) and is red in acid
solutions (here pH less than 3.1). This will allow you to determine when you have
reached the end point (i.e. the antacid has neutralized as much acid as it can).

4. Carefully fill the buret with 1 M hydrochloric acid. (M, molarity, is a measure of the
acid strength.) Run a few drops of acid into a spare beaker by opening the stopcock, and
discarding the acid in the sink, washing it down the drain with water. Then fill the buret
tip past the stopcock. Be certain that there are not air bubbles in the buret.

5. Read the level of acid in the buret. Read the volume, using the lower part of the
meniscus, as accurately as possible, estimating between the closest adjacent lines to
hundredths of the milliliter.

        initial level______________mL (2)
Red Rocks Community College

6. Place a sheet of white paper under the flask to more easily observe the color of the
contents. Carefully and slowly open the stopcock on the buret and add acid to the flask
while constantly stirring to mix the contents. Close the stopcock periodically and swirl
the flask. As you approach the end point, (the point at which all of the acid has been
neutralized) each drop of acid will turn the solution purple, but after swirling it will return
to green. At this point, add acid only one drop at a time. Continue to add acid, drop by
drop, swirling the flask after each drop is added. When the purple color persists for one
minute after swirling and an additional drop causes no deepening of the color, you have
reached the end point. That is, all the antacid chemical has been used up, and the last
drop of acid made the contents of the flask permanently acid. Record the final level of
acid in the buret.

        final level_______________mL (3)

7. Complete the Calculations and Question worksheet

Now move to the Computer Lab

   Each person in the group will have a different assignment
           o Assignment #1: Using Inspiration, develop a concept map of the lab.
              Use your imagination. The pics from the camera can be used.
           o Assignment #2 and #3: Using Publisher, develop a flyer to advertise
              which antacid is the best.
           o Assignment #4: Using Excel, graph the results from the Plop Table.
              Include Appropriate graphics.

 Plop Table
 Calculations/Question Sheet
 Inspiration concept map
 Publisher Flyer

Web Sites:

About Chemistry

   Chemistry Lesson Plans

Red Rocks Community College


   Acids and Bases

   Alternate version of the lab on the web

   Version of this lab without costly burets

   Technology Integration Lesson Plan

Red Rocks Community College