Chapter 5 - States of Matter - Gases, Liquids, and Solids
Changes in State
Changes in state are considered to be physical changes
During a change of physical state many other physical properties may also change
Gas Liquid Solid
Volume & Shape Expands to fill the volume of the Fixed volume at a given mass and temperature, Fixed volume, volume
container so it takes the shape of the volume is dependent on it's mass then on it's dependent on it's mass
container temperature, takes the shape of the container then on it's temperature,
has a definite shape
Density Low (typically 10−3g/mL) High (typically 1 g/mL) High (1 - 10 g/mL)
Compressibility (C = ΔV/ΔP) High Very low Virtually incompressible
Particle Motion Virtually free (KE > Attractive forces) Molecules or atoms "slide" past each other Vibrate at a fixed position
Intermolecular Distance Very large Molecules or atoms are close to each other Molecules, atoms, and ions
are close to each other
The Gaseous State
Ideal Gas: A model of the way that gas particles behave at the atomic/molecular level
1
, We can measure the following of a gas
Temperature
Volume
Pressure
Mass
We can systematically change one of these properties and see the effect on the others
Measurement of Gases
Gas laws involve the relationship between
Number of moles (n)
Volume (V)
Temperature (T)
Pressure (P)
Pressure: Force per unit area
Gas pressure is a result of force exerted by the collision of particles with the walls of the
container
Barometer
Measures atmospheric pressure
Invented by Evangelista Torricelli
Common units of pressure
Atmosphere (atm)
Torr (in Torricelli's honor)
Pascal (Pa) (in honor of Blaise Pascal)
1 atm = 760 mmHg = 760 torr = 76.0 cmHg
Kinetic Molecular Theory of Gases
Gases are made up of small atoms or molecules that are in constant, random, and linear
motion
2
Changes in State
Changes in state are considered to be physical changes
During a change of physical state many other physical properties may also change
Gas Liquid Solid
Volume & Shape Expands to fill the volume of the Fixed volume at a given mass and temperature, Fixed volume, volume
container so it takes the shape of the volume is dependent on it's mass then on it's dependent on it's mass
container temperature, takes the shape of the container then on it's temperature,
has a definite shape
Density Low (typically 10−3g/mL) High (typically 1 g/mL) High (1 - 10 g/mL)
Compressibility (C = ΔV/ΔP) High Very low Virtually incompressible
Particle Motion Virtually free (KE > Attractive forces) Molecules or atoms "slide" past each other Vibrate at a fixed position
Intermolecular Distance Very large Molecules or atoms are close to each other Molecules, atoms, and ions
are close to each other
The Gaseous State
Ideal Gas: A model of the way that gas particles behave at the atomic/molecular level
1
, We can measure the following of a gas
Temperature
Volume
Pressure
Mass
We can systematically change one of these properties and see the effect on the others
Measurement of Gases
Gas laws involve the relationship between
Number of moles (n)
Volume (V)
Temperature (T)
Pressure (P)
Pressure: Force per unit area
Gas pressure is a result of force exerted by the collision of particles with the walls of the
container
Barometer
Measures atmospheric pressure
Invented by Evangelista Torricelli
Common units of pressure
Atmosphere (atm)
Torr (in Torricelli's honor)
Pascal (Pa) (in honor of Blaise Pascal)
1 atm = 760 mmHg = 760 torr = 76.0 cmHg
Kinetic Molecular Theory of Gases
Gases are made up of small atoms or molecules that are in constant, random, and linear
motion
2
