A. Major Points and Concepts
Solids-they have a define shape and volume
Liquids-define volume but assumes the shape of the container
Gases-No define shape or volume
Liquid and Gas
Gases flow like liquids and are fluids
The difference between a gas and a liquid is the distance between the molecules.
Barometer
Barometer-a common instrument to measure air pressure
Pressure conversion
1 atm=760 mm Hg
1 atm=760 torr
1 atm=14.7 psi
1 atm=101325 Pa
Weight of air
Atmospheric pressure results from the mass of the air being pulled toward the center of the earth by gravity.
Boyle's law
The Irish scientist Robert Boyle (1627-1691) was one of the first scientist to carefully study gases. Using a J-shape tube closed at one end. He saw that there was a relationship between pressure and volume.
Pressure and volume are inversely proportional. If one doubles, the other decreases by one-half.
PV=PV
Assumption: temperature must be consistent
Charles' Law
The French physicist Jacques Charles (1746-1823) showed that the volume of a given amount of gas at constant pressure will increase with the temperature of the gas.
Temperature is proportional to volume. As temperature increases volume increases. As temperature decreases volume decreases.
V/T=V/T
Combined Gas Law
Assumption: Number of moles constant
This law combines both Boyle's law and Charles' law
PV/T=PV/T
Avogadro's Law
There is a relationship between the volume of a gas and the number of molecules present in the gas sample.
The number of moles is proportional to volume. As number of moles increases volume increases. As number of moles decreases volume decreases.
V/n=V/n
Ideal Gas Law
PV=nRT
R=universal gas constant
R=0.08206 L*atm/mol*K
ideal gas law was derived from the observation of Boyle's, Charles', and Avogadro's.
Assumption: the gas must be ideal
Ideal Gas
Kinetic molecular theory of gases is a relatively simple model that attempts to explain the behavior of an ideal gas.
1. Gases consist of tiny particles
2. These particles are so small, compared with the distances between them, that the volume(size) of the individual particles can be assumed to be zero.
3. the particles are constant random motion, colliding with the walls of the container. These collision with the walls cause the pressure exerted by gas.
4. The particles are assumed not to attract or to repel each other.
5. The average kinetic energy of the gas particles is directly proportional to the Kelvin temperature of the gas
Dalton's Law of Partial Pressure
Many important gases contain a mixture of components. John Dalton was one of the first scientist to study mixtures of gases. His observation became Dalton's law of partial pressure. For a mixture of gases in a container, the total pressure exerted is the sum of the partial pressures of the gases present.
Pressure of mixture of gases
Pressure of a gas is not based on the element
Liquids-define volume but assumes the shape of the container
Gases-No define shape or volume
Liquid and Gas
Gases flow like liquids and are fluids
The difference between a gas and a liquid is the distance between the molecules.
Barometer
Barometer-a common instrument to measure air pressure
Pressure conversion
1 atm=760 mm Hg
1 atm=760 torr
1 atm=14.7 psi
1 atm=101325 Pa
Weight of air
Atmospheric pressure results from the mass of the air being pulled toward the center of the earth by gravity.
Boyle's law
The Irish scientist Robert Boyle (1627-1691) was one of the first scientist to carefully study gases. Using a J-shape tube closed at one end. He saw that there was a relationship between pressure and volume.
Pressure and volume are inversely proportional. If one doubles, the other decreases by one-half.
PV=PV
Assumption: temperature must be consistent
Charles' Law
The French physicist Jacques Charles (1746-1823) showed that the volume of a given amount of gas at constant pressure will increase with the temperature of the gas.
Temperature is proportional to volume. As temperature increases volume increases. As temperature decreases volume decreases.
V/T=V/T
Combined Gas Law
Assumption: Number of moles constant
This law combines both Boyle's law and Charles' law
PV/T=PV/T
Avogadro's Law
There is a relationship between the volume of a gas and the number of molecules present in the gas sample.
The number of moles is proportional to volume. As number of moles increases volume increases. As number of moles decreases volume decreases.
V/n=V/n
Ideal Gas Law
PV=nRT
R=universal gas constant
R=0.08206 L*atm/mol*K
ideal gas law was derived from the observation of Boyle's, Charles', and Avogadro's.
Assumption: the gas must be ideal
Ideal Gas
Kinetic molecular theory of gases is a relatively simple model that attempts to explain the behavior of an ideal gas.
1. Gases consist of tiny particles
2. These particles are so small, compared with the distances between them, that the volume(size) of the individual particles can be assumed to be zero.
3. the particles are constant random motion, colliding with the walls of the container. These collision with the walls cause the pressure exerted by gas.
4. The particles are assumed not to attract or to repel each other.
5. The average kinetic energy of the gas particles is directly proportional to the Kelvin temperature of the gas
Dalton's Law of Partial Pressure
Many important gases contain a mixture of components. John Dalton was one of the first scientist to study mixtures of gases. His observation became Dalton's law of partial pressure. For a mixture of gases in a container, the total pressure exerted is the sum of the partial pressures of the gases present.
Pressure of mixture of gases
Pressure of a gas is not based on the element