Summer Research Program for Science Teachers
August 2012
Subject: Chemistry
Grade Level: 9
- 12
Unit: Bonding
Time Required: One
60 minute period plus time at home for analysis questions to be completed
Purpose: Students
will investigate properties of polarity
Objectives: ASWBAT:
·
Define polarity
·
Make scientific observations and record them
·
Apply knowledge of bonding to answer summative questions
Aim:
To marble paper
Materials:
Shaving cream (white)
Food coloring
Styrofoam plates
Small beaker or cup (100ml)
Wooden sticks
Paper towels
Tooth picks
Eye dropper
Index card/ card stock/ art paper water
Background:
Shaving cream is a mixture composed of a solid soap, water, and a gas.
Together these components form a lather which can be used as an agent to
aid in shaving without damaging the skin.
In addition, part of the shaving cream has a hydrophilic (“water loving”)
head and a hydrophobic (“water hating”) tail.
Another main ingredient in the shaving cream is a fatty acid. A fatty
acid is an organic acid which has an aliphatic tail that can either be saturated
or unsaturated. Depending on what
fatty acid is used the soap or lather will have different characteristics such
as forming more of a cream or more bubbly.
One of the common fatty acids that are used in making lather is stearic
acid. See figure 1 below.
Figure.1 Stearic Acid
Common paper is largely wood pulp which is composed of cellulose found in the
cell walls of green plants.
Cellulose is large chains of glucose molecules see figure 2 below.
Figure. 2 Glucose molecule
In this investigation you will be studying the properties of lather and its
interaction with food coloring. In
the process you will be able to create beautiful designed paper in the tradition
of the Japanese art form sumo nagashi (meaning “ink floating).
Procedure:
1)
Working in groups of two (2) design an experiment to determine the relationship
between the shaving cream, paper, and the food coloring using only the materials
on the material list. List your
procedure in the space provided below.
Be sure to make a testable hypothesis.
Be sure to identify the independent and dependent variable.
2)
Use the materials to create a colorful marbled design
Conclusion and analysis:
1)
List the ingredients on the can of shaving cream.
Circle how many of them you are familiar with.
Identify the group of compounds they belong to (i.e.- organic acid,
ketone, ionic, etc) if you can.
2)
Based on your observations, what claims con you tell about the polarity of the
food coloring and the paper? Explain
3)
Artists have created beautiful marble papers since the middle ages.
How do you think an artist’s understanding of materials influences his or
her work? Explain
National Education Standards
Unifying Concepts and Processes: Grades K–12
Evidence, models, and explanation
Content Standards: Grades 5–8
Content Standard B: Physical Science, properties and changes of properties in
matter
Content Standards: Grades 9–12
Content Standard B: Physical Science, structure and properties of matter