Solutions: Does 1+1 Always = 2? (SOL 4.1, 5.1 & 5.4)

Teacher Name: Gemma Griffin
Date: June 9, 2003
Subject: Science
Time: 30-45 minutes
Concept: Chemistry
Topic: Solutions, solutes, solvents
SOL: Science 5.4: Matter, 4.1 and 5.1 Scientific Investigation, Reasoning, and Logic

Rationale:

Science is not black and white. In order to promote students as good scientific thinkers, it is important to challenge them to think “outside the box” and consider the impossible. Making observations, conclusions, and predictions are important skills for students to develop. These skills will allow them to evaluate reported research, make better informed decisions as citizens, and become actively involved in issues that require them to question and process information.
Goal: To have students question and rethink what they knew to be fact.

Objectives:

Cognitive:

The student will be able to orally and in writing identify and differentiate solution, solute and solvent after completion of an experiment utilizing solutes and solvents. See attached rubric.

Affective:

The student will be able to orally and in writing re-evaluate his or her prior knowledge after completion of an experiment and worksheet, which asks them to question and rethink what they knew to be fact. See attached rubric.

The student will be able to work cooperatively in groups, as well as make individual contributions, during an experiment, evidenced by successful completion of the experiment.

Psychomotor:

The student will be able to participate, in groups, using scientific investigation skills, to complete an experiment, evidenced by completion of worksheet.

The student will be able to set up materials before the experiment, evidenced by successful completion of the experiment.

The student will be able to measure materials for the experiment using measuring cups, evidenced by successful completion of the experiment.

Materials:

For each group:

1 cup sugar
measuring cup
beaker that holds 2 cups
stirrers
water
plastic cups
paper towels
colored pieces of paper for grouping purposes

Advanced Organizer: 2 minutes

What does 1+1 equal?

Procedure: 30 minutes

I. Think Pair Share (10 minutes)

1. Teacher poses a Question:

Do you believe that in every situation 1+1 will always equal 2?

2. Have students take out a sheet of paper/pencil and think individually and record in writing for a minute or two about the problem.

3. Have students partner up and discuss his or her ideas with a fellow student for about 2 minutes, or depending on discussion atmosphere of the students.

4. Have students share their ideas with the whole class. Students can present their ideas individually or cooperatively in pairs.

II. 1 cup + 1 cup = ???? Experiment with matter. (20 minutes)

A. Have students form small cooperative groups of 3-4. Assign groups using colored pieces of paper.

B. Give each student one data sheet with directions for the experiment, and each group the following materials:

2 cups sugar
measuring cup
spoon
water
beaker
paper towels

C. Directions for the experiment:

1. Measure out 1 cup of water and pour it into the beaker.

2. Use masking tape to mark the 1 cup point.

3. Measure out another cup of water. Pour into the beaker. There should be 2 cups of water in the beaker. Mark with masking tape the 2 cup mark. Did 1 cup of water plus 1 cup of water equal 2 cups of water?

4. Pour water out, and dry the beaker very well. Also dry measuring cup well.

5. Pour sugar into beaker to the one cup mark. The pour sugar to the 2 cup mark. Did 1 cup of sugar plus 1 cup of sugar equal 2 cups of sugar?

6. Pour out sugar from the beaker back into the bag.

7. Pour water into the beaker to the 1 cup mark.

8. Dry the measuring cup and measure 1 cup of sugar. Add it to the beaker with water. Stir well.

9. Does 1 cup of water plus 1 cup of sugar equal 2 cups?

10. Does 1 + 1 always equal 2?

Results: Students will find that 1 cup sugar plus 1 cup water will equal less than 2 cups. The reason for this follows along the line that no two pieces of matter can occupy the same space at the same time. Sugar is not completely solid. There are little spaces between the sugar grains where the water moves into, thus reducing the total amount of the solution.

Closure 5 minutes

After the experiment, have students come together and discuss their findings.

Did the conclusion cause them to reevaluate their hypothesis? Does 1+1 always equal 2?

Why do they think 1 cup sugar plus 1 cup water doesn’t equal 2?

(Help guide students to chemical reaction and solution explanation here).