Reviewer in Science
Reviewer in Science
Reviewer in Science
GASES AND KINETIC MOLECULAR THEORY POSTULATE 2: The collision of gas particles is elastic.
When gas particles collide, no energy is lost or gained
GAS
between them, and the total kinetic energy of the
Are generally invisible matter that occupies particles remains constant.
nearly all spaces in the environment.
POSTULATE 3: The average kinetic energy of gas
PROPERTIES OF GAS: particles is directly proportional to their absolute
1. Gas particles come in the form of atoms or temperature (kelvin). The higher the temperature of the
molecules. gas molecules, the greater is their average kinetic
2. Gases match the shape and volume of their energy.
containers.
3. The distance among gas particles are larger than POSTULATE 4: The intermolecular forces among gas
the distances among particles of liquid and particles are negligible. Any attractive or repulsive
solid. forces arising among the particles when they interact
4. Gas particles are highly compressible. are immensely weak and unable to hold them together.
5. Gas particles move free, constant, and random
motion. POSTULATE 5: The volume of gas particles are negligible
6. Intermolecular forces among gas particles are relative to the volume of their container in the other
weak and negligible. words, the volume of gas depends on how much space
7. Gases act upon changes in temperature. the gas particles occupy within the container.
8. Gas particles diffuse or spread out.
PRESSURE= FORCE/AREA
2. TEMPERATURE (T) CHARLES’ LAW
- The measurement of the kinetic energy of Jacques Charles (1746-1823)
the gas particles. States that volume is directly proportional to
- Standard unit for temperature is Kelvin or K the temperature at constant pressure.
- Other units of temperature: A gas expands when its temperature increases.
Degrees Celsius = C It contracts when temperature decreases.
Degrees Fahrenheit = F Charles’ law states that given a fixed amount of
- absolute zero (0 kelvin) is equivalent to (- gas with constant pressure, the volume is
273.15 C) directly proportional to its absolute
temperature.
The standard freezing temperature of 0 C is Charles’ law expressed as:
equivalent to 273.15 K
- Conversion:
K = C + 273
C = K – 273
3. VOLUME (V) GAY-LUSSAC’S LAW
- Refers to the amount of space occupied by Joseph Louis Gay-Lussac (1778-1850)
the gas particles. Pressure is directly proportional to temperature
- The standard unit for volume is liter or L Gay-lussac’s law is expressed as:
4. AMOUNT OF GAS (n)
- The amount of gas is measured in relation
to the volume of particles at a specific
temperature and pressure.
- The standard unit for the amount of gas is AVOGADRO’S LAW
the mole or mol States that equal volume of different gases with
the same temperature and pressure contain
GAS LAWS equal numbers of moles.
Volume is directly proportional to amount of
BOYLE’S LAW gas
Robert Boyle (1627-1691) Avogadro’s law is expressed as:
Boyle’s law states that the pressure is inversely
proportional to the volume at constant
temperature.
When volume increases, pressure decreases.
When the volume decreases, pressure COMBINED GAS LAW
increases. Combines the first three gas laws: boyle’s,
Boyle’s law states that at constant temperature, charles’, and gay-lussac’s law.
the volume of a fixed amount of gas is inversely States the ratio between the pressure and
proportional to its pressure. temperature of gases is directly proportional to
the volume of the gas.
Combined gas law is expressed as: