kinetic theory of gases
Kinetic theory of gases
Question:
How does odor travel from one place to another?
Kinetic theory of gases
A gas is composed of atoms or molecules
The gas particles are in constant random motion
Kinetic energy is transferred between particles as they collide
Pressure
The force exerted per unit of area
Formula: pressure/force area
Measured by barometer
A vacuum is empty space, with no particles or pressure.
Atmospheric pressure is the collision air particles with objects
Units of pressure
Kilopascals (kPa)
Atmospheres (atm)
Millimeters of mercury (mmHg)
Temperature
What happens to the motion of gas molecules if the gas is heated?
As a gas is heated, the molecules move faster and the temperature rises.
As a gas cools, the molecules move slower and the temperature lowers.
If the gas cools to the point that the molecules stop moving, the gas has reached absolute zero.
Standard temperature and pressure (STP)
The pressure and temperature where 1 mole of gas has a volume of exactly 22.4 liters of volume.
101.3 kPa
1 atm
760 mmHg
0 degrees Celsius
273 kelvins
Converting between pressures set up a dimensional analysis calculation similar to mole conversions
101.3 kPa = 1 atm = 760 mmHg if the air pressure is 842 mmHg, how many kPa is that?
842 mmHg / 101.3 kPa / 760 mmHg = 112.3 kPa
Converting temperatures why use kelvins? No negative temps.
0 degrees Celsius equals 273 kelvin tochange Celsius to kelvin add 273 to change kelvin to Celsius subtract 273
if the room temperature is 22 degrees Celsius, what is it in kelvins?
On your own
Convert 1.50 atm to kPa and mmHg
1.50 atm/101.3 kPa / 1 atm = 151.95 kPa
1.50 atm / 760mmHg / 1 atm = 1140 mmHg
Convert 150 K to degrees Celsius (Celsius + 273 = kelvin, opposite when finding Celsius)
150 – 273 = -123
The boiling point of water is equal to 373 K
The freezing
Question:
How does odor travel from one place to another?
Kinetic theory of gases
A gas is composed of atoms or molecules
The gas particles are in constant random motion
Kinetic energy is transferred between particles as they collide
Pressure
The force exerted per unit of area
Formula: pressure/force area
Measured by barometer
A vacuum is empty space, with no particles or pressure.
Atmospheric pressure is the collision air particles with objects
Units of pressure
Kilopascals (kPa)
Atmospheres (atm)
Millimeters of mercury (mmHg)
Temperature
What happens to the motion of gas molecules if the gas is heated?
As a gas is heated, the molecules move faster and the temperature rises.
As a gas cools, the molecules move slower and the temperature lowers.
If the gas cools to the point that the molecules stop moving, the gas has reached absolute zero.
Standard temperature and pressure (STP)
The pressure and temperature where 1 mole of gas has a volume of exactly 22.4 liters of volume.
101.3 kPa
1 atm
760 mmHg
0 degrees Celsius
273 kelvins
Converting between pressures set up a dimensional analysis calculation similar to mole conversions
101.3 kPa = 1 atm = 760 mmHg if the air pressure is 842 mmHg, how many kPa is that?
842 mmHg / 101.3 kPa / 760 mmHg = 112.3 kPa
Converting temperatures why use kelvins? No negative temps.
0 degrees Celsius equals 273 kelvin tochange Celsius to kelvin add 273 to change kelvin to Celsius subtract 273
if the room temperature is 22 degrees Celsius, what is it in kelvins?
On your own
Convert 1.50 atm to kPa and mmHg
1.50 atm/101.3 kPa / 1 atm = 151.95 kPa
1.50 atm / 760mmHg / 1 atm = 1140 mmHg
Convert 150 K to degrees Celsius (Celsius + 273 = kelvin, opposite when finding Celsius)
150 – 273 = -123
The boiling point of water is equal to 373 K
The freezing