Intermolecular Forces and Adhesives
Subject Area: Chemistry
Grade Level: High School Chemistry
Lesson Title: Intermolecular Forces and Adhesives
National Science Education Standards:
 Science as Inquiry: 9–12
Physical Science Standards:
 Structure of molecules: 9–12
 Structure and properties of matter: 9–12
 Chemical reactions: 9–12
Suggested Prior Knowledge: polar molecules, dipole moments, intermolecular forces
Purpose: To demonstrate van der Waals (intermolecular) forces, viscosity, adhesion, and
cohesion and their relationship to adhesives by having students conduct an experiment to test the
effectiveness of three different types of glue on three different materials at room temperature and
at refrigerator temperature.
Key Vocabulary:
adhesion—the force of attraction between unlike molecules; the property of a material that
allows it to stick better to something else than to itself
cohesion—the force of attraction between like molecules; the property of a material that
allows it to stick better to itself than to something else
dipole moment—the measure of net molecular polarity, where if the difference in
electronegativity between atoms is sufficient the resulting molecule will be polar
intermolecular force—an attraction between molecules that holds them together, such as:

dipole-dipole force—result of electrical interactions among neutral but polar
molecules

hydrogen bond—result of electrical interaction between a hydrogen atom bonded to
an electronegative O,N, or F atom and an unshared electron pair on another nearby
electronegative atom
Intermolecular Forces and Adhesives (High School Lesson)
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
ion-dipole force—result of electrical interactions between an ion and the partial
charges of a polar molecule

London dispersion force—result of instantaneous and temporary electrical
interaction among molecules that are electrically neutral and that have a zero dipole
moment
van der Waals forces—an alternative name for intermolecular forces, in honor of Dutch
scientist Johannes van der Waals
viscosity—the measure of a liquid’s resistance to flow. It is also a term for the ease with
which molecules flow in relation to intermolecular forces.
Objectives:
1. Students will experience intermolecular forces through experimentation
2. Students will be able to describe how adhesives relate to intermolecular forces
Materials (each group should receive the following):
- student worksheet
- 4 oz bottle of white glue
- small bottle of rubber cement
- 4 oz bottle of wood glue
- (12) 4.25″ × 5.5″ rectangles of acetate (transparency sheets). Cut one 8.5” x 11”sheet into four
pieces
- (12) 4.25″ × 5.5″ rectangles of cardboard
- (12) 4.25″ × 5.5″ rectangles of heavy duty aluminum foil
- access to a refrigerator
- goggles and lab safety equipment as needed
- permanent marker
Procedure:
1. Discuss intermolecular forces and their varying relationships to liquids and solids with
students by asking them the following questions:
 Can you give an example of a liquid and identify the intermolecular forces involved (e.g.,
H2O and hydrogen bonding)?
 What is the connection between intermolecular forces and solids?
 What effect can temperature have on intermolecular forces?
 How do you think glues work?
 What characteristics do glues share with liquids and solids?
 What effect will temperature have on adhesives such as glue?
2. Divide the class into groups of four and provide the materials for each group. The acetate,
cardboard, and aluminum will represent surface materials. Each adhesive will be tested in its
ability to bond with each surface material at room temperature and at refrigerator temperature.
3. Facilitate a discussion on experimental procedure. Some of the following questions can help:
Intermolecular Forces and Adhesives (High School Lesson)
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



How can we test the intermolecular forces of each adhesive?
Who can provide a hypothesis for this experiment?
What variables do we need to account for?
What data should we collect?
4. Begin the experiment by having the students record the room temperature and refrigerator
temperature.
5. Paint a consistent sized circle of each adhesive between two pieces of each material, gluing
them together. Make two sets, one that will go into the refrigerator and one that will stay at room
temperature.
6. Mark each sample with a relevant sample identification (use the Sample Identification Key on
the student worksheet as a reference). Set nine test samples aside to cure at room temperature
and put the other nine samples in the refrigerator.
7. Record the time at which all of the samples have begun to cure.
8. After approximately 24 hrs (suggested time interval) remove all of the samples from their
curing locations.
9. Have the group appoint a person as the official “force applier.” Taking the refrigerated
samples first, have that person try to separate each sample by gradually applying a pulling force
to the materials. By observing their “force applier,” the group should rate the ability of the
intermolecular forces to hold the material together using a scale in which 1 is the weakest and 5
is the strongest.
10. Have each group discuss their findings and create their conclusion.
Additional Resources:
 http://www.chemistryexplained.com/A-Ar/Adhesives.html
 http://www.chem.ufl.edu/~itl/2045/lectures/lec_g.html
 http://www.explainthatstuff.com/adhesives.html
Intermolecular Forces and Adhesives (High School Lesson)
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Student Worksheet for Intermolecular Forces and Adhesives
Experiment Title: ________________________________ Date: ________ Name: _______
Student Hypothesis:
___________________________________________________________________________
Materials:
___________________________________________________________________________
Procedure:
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
______________________________________________________________________________
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Data:
Refrigerator
________°C
Room
________°C
Timei
Timef
Total Time
Sample Identification Key
White Glue
Rubber Cement
Wood Glue
Acetate
White
____°C
Acetate
Rubber
____°C
Acetate
Wood
____°C
Acetate
Acetate
White
____°C
Acetate
Rubber
____°C
Acetate
Wood
____°C
Acetate
Cardboard
White
____°C
Cardboard
Rubber
____°C
Cardboard
Wood
____°C
Cardboard
Cardboard
White
____°C
Cardboard
Rubber
____°C
Cardboard
Wood
____°C
Cardboard
Aluminum
White
____°C
Aluminum
Rubber
____°C
Aluminum
Wood
____°C
Aluminum
Aluminum
White
____°C
Aluminum
Rubber
____°C
Aluminum
Wood
____°C
Aluminum
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Intermolecular Forces and Adhesives (High School Lesson)
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Acetate
________°
C
Acetate
________°
C
Cardboard
________°
C
Cardboard
________°
C
Aluminum
________°
C
Aluminum
________°
C
White Glue
Rubber Cement
Observations
Wood Glue
Describe the effect of temperature on the cohesive forces for each adhesive:
White Glue:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Rubber Cement:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Wood Glue:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Describe the effect of temperature on the adhesive forces for each adhesive:
White Glue:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Rubber Cement:
______________________________________________________________________________
Intermolecular Forces and Adhesives (High School Lesson)
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______________________________________________________________________________
______________________________________________________________________________
Wood Glue:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Conclusion (use the back if necessary):
______________________________________________________________________________
______________________________________________________________________________
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