The document discusses intermolecular forces and their effect on the properties of substances. It provides guidance cards that define the four main types of intermolecular forces - hydrogen bonding, dipole-dipole forces, ion-dipole forces, and London dispersion forces. The cards explain how these forces are responsible for determining if a substance is a solid, liquid or gas. Several activities and assessments are included to help students identify the different intermolecular forces in various compounds and rank their relative strengths.

1. Page 1
Arnel S. Miraflor, Ed.D.

2. Page
Least Mastered Learning Competencies
Describe the general types of intermolecular forces
1. Give the type of intermolecular forces in the properties of
substances;
15/27 learners
2. Explain the effect of intermolecular forces on the properties of
substances.
12/27 learners
Task Analysis
• How the uses of different materials are
related to their properties and
structures?
• Why do some solids dissolve in
water but others do not?
• Why some substances gases at
room temperature, but others are
are liquid or solid?
Do you know the answer?
No! ! Can
you help me?
Guide Card 1
111111CCardCa
rd 1
Name is Bond,
HYDROGEN BOND.
I have some questions for you.
I am Atom, I am a
student.
Sure! Stay, read and
understand the
following guide cards.
2

3. Page
Guide Card 2
2CCardCa
rd 1
Bonding makes water behave like
what you see in the picture.
Wow!
3

4. Page
Guide Card 3
3CCardCa
rd 1
Intermolecular Forces
Intermolecular forces are attractive forces between molecules. They are
largely responsible for the observed boiling points and solubility properties of
molecules.
The physical properties of melting point, boiling point, vapor pressure,
evaporation, viscosity, surface tension, and solubility are related to the
strength of attractive forces between molecules.
These attractive forces are called Intermolecular Forces. The amount of "stick
togetherness" is important in the interpretation of the various properties listed
above.
There are four types of intermolecular forces. Most of the intermolecular
forces are identical to bonding between atoms in a single molecule.
Intermolecular forces just extend the thinking to forces between molecules
and follows the patterns already set by the bonding within molecules.
4
Type of Bond Electronegativity Diffence
Ionic ≥ 2.0
Polar covalent 0.5 to < 2.0
Nonpolar Covalent < 0.5
Wow!
So that’s how
we identify if
the molecule is
polar, nonpolar
or ionic.

5. Page
London forces
only (induced
dipoles)
Examples: Ar , I2
Interacting molecules or Ions
No No Yes No
Are Hydrogen atoms
bonded to N, O, or F
atoms?
No
Yes
Yes
Dipole-dipole
forces
Examples: H2S,
CH3Cl
Hydrogen bonding
Examples: Liquid
and solid H2O, NH3,
HF
Ion-dipole forces
Example: KBr in
H2O
Ionic bonding
Examples: NaCl,
NH4 NO3
Yes
Van der Waals Forces
Are polar
molecules
involved?
Are ions
involved
?
Are polar molecules
and ions both
present?
5
Guide Card 4
Now I know.

6. Page
Guide Card 5
What determines if a substance is a solid, liquid, or gas?
Gas
Total disorder; much empty
space; particles have
complete freedom of
motion; particles far apart.
Liquid
Disorder; particles or clusters
of particles are free to move
relative to each other;
particles close together.
Crystalline solid
Ordered arrangement; particles
are essentially in fixed positions;
particles close together.
Cool
Heat
Cool or
compress
Heat or reduce
pressure
Gases: The average kinetic energy of the gas molecules is much larger than the average energy of the attractions between them.
Liquids: the intermolecular attractive forces are strong enough to hold the molecules close together, but without much order.
Solids: the intermolecular attractive forces are strong enough to lock molecules in place (high order).
6

7. Page
Inner electrons Outer electrons
Slight repulsion
Of “like”
Negative charges
Guide Card 6
The forces holding ions together in ionic solids are electrostatic
forces. Opposite charges attract each other.
These are the strongest intermolecular forces. Ionic forces hold
many ions in a crystal lattice structure.
Ionic Bonding
Na +1
Cl -1 Ionic Bond
Sodium Chloride, NaCl
Na + →  Cl –
Main Ionic Effect: Opposite charges attract
Na+
Cl-
7

8. Page
Guide Card 7
Hydrogen Bonding
H-bonding is a special type of dipole - dipole attraction that is very strong
It occurs when N, O, or F are bonded to H
▪ Q- Using periodic table of elements, Calculate the Electron
Negativity for HCl and H2O
HCl = 2.9-2.1 = 0.8, H2O = 3.5-2.1 = 1.4
The high EN of NH, OH, and HF bonds cause these to be strong forces (about
5x stronger than normal dipole-dipole forces)
They are given a special name (H-bonding) because compounds containing
these bonds are important in biological systems
Consider two water molecules coming close together.
The + hydrogen is so strongly attracted to the lone pair that it is almost as if you
were beginning to form a co-ordinate (dative covalent) bond. It doesn't go
that far, but the attraction is significantly stronger than an ordinary dipole-
dipole interaction.
8

9. Page
London Forces
• Non-polar molecules do not have dipoles like polar molecules. How, then, can non-polar
compounds form solids or liquids?
• London forces are named after Fritz London (also called van der Waal forces)
• London forces are due to small dipoles that exist in non-polar molecules
• Because electrons are moving around in atoms there will be instants when the charge around an
atom is not symmetrical
• The resulting tiny dipoles cause attractions between atoms/molecules.
Guide Card 8
9

10. Page
Polar covalent molecules are sometimes described as "dipoles",
meaning that the molecule has two "poles". One end (pole) of
the molecule has a partial positive charge while the other end
has a partial negative charge. The molecules will orientate
themselves so that the opposite charges attract principle
operates effectively.
Guide Card 9
Dipole Forces
10
So those are the different
intermolecular forces

11. Page
Direction: Using the periodic table below, determine the kind/s of intermolecular forces that are present in each of the
following elements or compounds: Choose your answer/s below.
Dispersion forces only; dispersion and dipole-dipole forces hydrogen bonds
Dispersion force, dipole-dipole forces,
(a) Kr
(b) NCl3
(c) SiH4
(d) HF
(e) N2
(f) NH3
(g) CO
(h) CCl4
Activity Card 1
11

12. Page
3
I
Direction: Using your knowledge of molecular structure, identify the main Inter molecular force in the following compounds.
a) PF3
b) H2CO
c) HF Be careful
with your
answer.
Good
luck!
Activity Card 2
Guide Card

13. Page
Good
luck!
Activity Card 2
Guide Card
Intermolecular Forces
Direction: Identify the strongest force present in pure
samples of the following substances:
1. SO3
2. CO2
3. PCl3
4. H2O
5. C2H6
6. NH3
12
13

14. Page
Direction: Rank the following substances from weakest intermolecular forces to strongest.
1. H2S
2. I2
3. N2
4. H2O
Activity Card 3
Guide Card
Wow! You’re
doing great.
14

15. Page
Activity Card 4
Guide Card
Direction: List the type(s) of intermolecular forces that are present in each of the following examples:
a. HBr
b. I2
c. CS2
d. H2O
e. CH2Cl2
f. C2H6
g. NH3
h. H2S
i. ClF3
15
Good luck!

16. Page
Direction: Rank the following substances from weakest intermolecular forces to strongest.
A.
✓ H2S
✓ I2
✓ N2
✓ H2O
B.
✓ H2Se
✓ H2S
✓ H2Po
✓ H2Te
Be
careful
Assessment Card
16

17. Page
Direction: For each pair of compounds, pick the one with the higher boiling point.
(a) NH3 or CH4
(b) CS2 or CO2
(c) CO2 or NO2
Enrichment Card
Best of
luck! You
can do it!
17

18. Page
Padolina, Ma. Cristina D., et. al. Physical Science. Vibal Group Inc.. 2016.
Reference Card
Card
18

19. Page
Answer Card
Activity Card 1
a) PF3 dipole-dipole
force
b) H2CO dipole-dipole
force
c) HF hydrogen bonding
Activity Card 2
1. SO3 - London dispersion
2. CO2 - London dispersion
3. PCl3 - Dipole‐ dipole
4. H2O - Hydrogen
5. C2H6 - London dispersion
6. NH3 - Hydrogen
Activity Card 3
N2 < I2 < H2S < H2O
N2 and I2 contain nonpolar molecules.
The only forces that attract them to Each other are London dispersion
forces. I2 has higher porarizability because iodine atom is much bigger
than the nitrogen atom. So, the attraction between I2 molecules is much
stronger than between N2 molecules. Both H2S and H2O are polar
molecules, But H2O is able to make hydrogen bonding => much stronger
attraction.
Activity Card 4
1. HBr dipole / LDF
2. I2 LDF (dispersion)
3. CS2 LDF
4. H2O Hydrogen bonding / dipole /
LDF
5. CH2Cl2 dipole / LDF
6. C2H6 dispersion
7. NH3 hydrogen bonding / dipole /
dispersion
8. H2S dipole / dispersion
9. ClF3 dipole / dispersion
Enrichment Card
(a) NH3
(b) CS2
(c) NO2
Assessment Card
A.
1. N2
2. I2
3. H2S
4. H2O
B.
1. H2S
2. H2Se
3. H2Te
4. H2Po
Congratulations!
You did it!
19

20. Page
How well did you learn from this lesson?
I fully understand the concepts and their applications.
( My score is _________)
I partially understand the concepts and their Applications
( My score is _________ )
I still do not understand the concepts and their applications
( My score is _________)
30
My Score
/ 40
Good job!
20