1. DO NOW: Rank the following phases of matter in order from least to greatest for… A) Energy B) Intermolecular Forces
High Energy
Medium Energy
Low Energy
Weak
Intermolecular
Forces
Medium
Intermolecular
Forces
Strong
Intermolecular
Forces
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 441

2. Phases/States of Matter
Gas
Shape of Container
Volume of Container
Solid
Liquid
ENERGY
ENERGY
Holds Shape
Fixed Volume
Shape of Container
Free Surface
Fixed Volume
Solid
In a solid the molecules are closely bound to one another by molecular forces. A solid holds its shape and the volume of a solid is fixed by the shape of the solid.
Liquid
In a liquid the molecular forces are weaker than in a solid. A liquid will take the shape of its container with a free surface in a gravitational field. In microgravity, a liquid forms a ball inside a free surface. Regardless of gravity, a liquid has a fixed volume.
Gas
In a gas the molecular forces are very weak. A gas fills its container, taking both the shape and the volume of the container

3. SOLID – e.g. ice
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

4. LIQUID – e.g. water some writing from Kotz (PowerPoint online)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31

5. Gas – e.g. steam
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 31

6. Some Properties of Solids, Liquids, and Gases
Property Solid Liquid Gas
Shape Has definite shape Takes the shape of Takes the shape
the container of its container
Volume Has a definite volume Has a definite volume Fills the volume of
the container
Arrangement of Fixed, very close Random, close Random, far apart
Particles
Interactions between Very strong Strong Essentially none
particles
The three common phases (or states) of matter are gas, liquid, and solid
1. Gases
a. Have the lowest density of the three states of matter
b. Are highly compressible
c. Completely fill any container in which they are placed
d. Their intermolecular forces are weak
e. Molecules are constantly moving independently of the other molecules present
2. Solids
a. Dense
b. Rigid
c. Incompressible
d. Intermolecular forces are strong
e. Molecules locked in place
3. Liquids
b. Incompressible
c. Flow readily to adapt to the shape of the container
d. Sum of the intermolecular forces are between those of gases
and solids
• The state of a given substance depends strongly on conditions

7. States of Matter Deposition Vaporization
Solid, Liquid, Gas are the three states of matter we will deal with.
Plasma and Neutron star are also states of matter.
For more information about plasma and neutron stars try the following links:
Coalition for Plasma Science – What is plasma?
Neutron Stars and Pulsars – Introduction

8. release energy and form intermolecular bonds
Liquids
The two key properties we need to describe are
EVAPORATION and its opposite CONDENSATION
add energy and break intermolecular bonds
EVAPORATION
CONDENSATION
release energy and form intermolecular bonds

9. Equilibrium is reached when:
Rate of Vaporization = Rate of Condensation
Molecules are constantly changing phase - dynamic
The total amount of liquid and vapor remains constant

10. Heating Curve for Water
Heating curve with pictures
Create a curve!!
Heating Curve for Water
vaporization E
gas D
100
condensation C
liquid
melting
Temperature (oC)
Melting, freezing, vaporization, condensation, sublimation, and deposition are six common phase changes.
Note: The temperature of a substance does not change during a phase change. B A
freezing
solid
Heat added
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487

11. Triple Point Plot melting freezing liquid solid Pressure (atm)
vaporization
condensation
Pressure (atm)
0.6
2.6
sublimation
deposition
gas
Temperature (oC)
LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 488

12. 1. Calculate the energy required to melt 8. 5g of ice at 0°C
1.Calculate the energy required to melt 8.5g of ice at 0°C. The molar heat of fusion for ice is 6.02kJ/mol. 2.Calculate the energy in kJ required to heat 25g of liquid water from 25°C to 100°C and change it into steam at 100°C. The specific heat capacity of liquid water is 4.18J/g°C, and the molar heat of vaporization of water is 40.6kJ/mol.

13. Calculate the energy required to melt 8. 5g of ice at 0°C
Calculate the energy required to melt 8.5g of ice at 0°C. The molar heat of fusion for ice is 6.02kJ/mol.

14. Calculate the energy in kJ required to heat 25g of liquid water from 25°C to 100°C and change it into steam at 100°C. The specific heat capacity of liquid water is 4.18J/g°C, and the molar heat of vaporization of water is 40.6kJ/mol.

16. Given that the specific heat capacities of liquid water, ice and steam are 4.18J/g°C, 2.06J/g°C & 2.03J/g°C, respectively and considering the molar heats of fusion & vaporization for water are 6.02kJ/mol & 40.6kJ/mol respectively, calculate the total quantity of heat evolved when 10.0 g of steam at 200.°C is condensed, cooled, and frozen to ice at -50°C.
(HINT: 5 step problem!)

17. Intermolecular Forces
Irresistible attraction…

18. ATTRACTIVE FORCES
Always electrostatic in nature
Intramolecular forces
bonding forces
These forces exist within each molecule.
They influence the chemical properties of the substance.
Intermolecular forces
nonbonding forces
These forces exist between molecules.
They influence the physical properties of the substance.

19. Intermolecular forces (IMF)
London dispersion forces: The forces that exist among noble gas atoms and non-polar molecules
Dipole-dipole attraction: Molecules with dipole moments (polar molecules) can attract each other by lining up so that the positive and negative ends are close to each other.
Hydrogen bonding: when hydrogen is bonded to a highly electronegative -FON
Increasing Strength of IMF

21. Dispersion Force

22. Examples: CO2, Ar, N2 Dispersion forces among nonpolar molecules.
separated Cl2 molecules
instantaneous dipoles
Examples: CO2, Ar, N2

23. Increase in MM (molar mass) = Increase in London Dispersion Forces

24. Dipole–Dipole Attractions
Polar molecules have a permanent dipole
because of bond polarity and shape
dipole moment
as well as the always present induced dipole
The permanent dipole adds to the attractive forces between the molecules
raising the boiling and melting points relative to nonpolar molecules of similar size and shape

25. Polar molecules and dipole-dipole forces.
solid
liquid
Examples: HF, HCl, NH3

26. H Bond Video
Hydrogen Bonding
When a very electronegative atom is bonded to hydrogen, it strongly pulls the bonding electrons toward it
O─H, N─H, or F─H
Because hydrogen has no other electrons, when its electron is pulled away, the nucleus becomes deshielded
exposing the H proton
The exposed proton acts as a very strong center of positive charge, attracting all the electron clouds from neighboring molecules

27. H-Bonding HF

28. Hydrogen bonding in H2O
Surface tension
Capillary action
Viscosity

29. Effects of strong intermolecular forces
Greater IMF = Increase MP &BP, Decrease in Vapor Pressure