Gas Joseph Louis Gay-Lussac
● The word gas comes from the Greek khas, meaning Gay-Lussac's Law | Direct: Pressure is directly proportional
“chaos” – reflecting the random, chaotic motion of gas absolute temperature if the volume is constant.
particles. ↑ Temperature = ↑ Pressure
Characteristics of Gases ● Celsius to Kelvin: K = C + 273.15
● Gases exhibit fluidity and have measurable flow rate, ● Kelvin to Celsius: C = K - 273.15
volume, and pressure. ● At 0 Kelvin (absolute zero), its particles would b
● According to fluid mechanics, gases and their particles stationary, and the gas would cease to exist in its gaseou
can be considered fluids. state, instead becoming a solid or liquid depending on th
● No fixed shape or volume––gases take the shape and substance.
volume of their container. 𝑃1 𝑃2 𝑃
● Gas particles move freely and rapidly in random motion.
𝑃α𝑇 | 𝑇1
= 𝑇2
| 𝑇
=𝑘
● Gases are compressible and expand to fill any available Ideal Gas: Theoretical gas composed of many random
space. moving point particles that do not experience interpartic
Kinetic Molecular Theory (KMT): A model used to explain gas interactions.
behavior accurately. It consists of five postulates: ● No interparticle forces: No attractive or repulsiv
1. Constant Motion – particles move in straight lines interactions.
randomly. ● Does not condense: Remains a gas even at lo
2. Negligible Volume – the size of gas particles is tiny temperatures.
relative to the space between them. ● Particles have no volume: The only volume considered
3. Elastic Collisions – no loss of kinetic energy during that of the container.
collisions. Aspect Ideal Gas Real Gas
4. Pressure – caused by collisions of particles with Intermolecular Present (attractive
None
container walls. Forces & repulsive)
5. Kinetic Energy – directly proportional to temperature Particle Volume Negligible Finite
(in Kelvin). Can condense at
Additional Assumptions: Condensation Does not condense
low temperatures
● Gas particles experience negligible intermolecular forces Deviates at high
(no attraction or repulsion). Obey Ideal Gas Law
Behavior pressure & low
● Gravitational and electromagnetic forces between gas perfectly
temperature
particles are ignored.
Gas Unit Conversions Ideal Gas Law: States that under the same temperatur
● 1 kP: 1,000 Pa pressure, and volume, all gases contain the same number
● 1 atm: 101.325 kPa : 101,325 Pa molecules but not the same mass.
● 1 Bar: 0.987 atm : 100 kPa : 100,000 Pa
𝑃𝑉 = 𝑛𝑅𝑇
● 1 Torr: 0.00131579 atm : 133.322 Pa
● P – Pressure
Lorenzo Romano Amedeo Carlo Avogadro
● V – Volume
Avogadro's Number (6.02 × 10²³): A fundamental constant in
● n – no. of moles
chemistry. Represents the number of particles (atoms,
● R – Proportionality Constant
molecules, ions, etc.) in one mole of a substance.
● T – Temperature
♡ Avogadro’s Law | Direct: Equal volumes of gases at the
Proportionality Constant (k/R): Fixed value that relates tw
same T and P contain the same number of molecules (n).
variables in a gas law equation. It ensures the mathematic
↑ Volume = ↑ Moles
relationship between gas properties remains consistent.
𝑉1 𝑉2 𝑉
𝑉α𝑛 | 𝑛1 = 𝑛2 | 𝑛 = 𝑘 Value of R Units Used When…
Sir Robert Boyle, FRS Used in
Boyle's Law | Inverse: Volume is inversely proportional to energy-related
pressure if the temperature is constant. calculations,
↑ Pressure = ↓ Volume Joules per mole including
8.314 J/(mol·K)
per Kelvin thermodynamics,
1 kinetic energy, and
𝑃α 𝑉 | 𝑃1𝑉1 = 𝑃2𝑉2| 𝑃𝑉 = 𝑘 work involving
Jacques Charles gases.
Charles' Law | Direct: Volume is directly proportional to Used when
absolute temperature if the pressure remains constant. pressure is in
↑ Temperature = ↑ Volume atmospheres (atm
𝑉1 𝑉2 𝑉 0.0821 Liters · atmosphere and volume is in
𝑉α𝑇 | 𝑇1 = 𝑇2 | 𝑇 = 𝑘 L·atm/(mol·K) per mole per Kelvin liters (L). Common
When the temperature of a gas sample increases: in chemistry and
● Gas particles move faster. general gas law
● Collisions with the container walls become more frequent. problems.
● Each collision exerts a greater force due to increased
kinetic energy.
● To maintain constant pressure, the gas must expand and
occupy a larger volume, reducing the frequency of
collisions per unit area.
● The word gas comes from the Greek khas, meaning Gay-Lussac's Law | Direct: Pressure is directly proportional
“chaos” – reflecting the random, chaotic motion of gas absolute temperature if the volume is constant.
particles. ↑ Temperature = ↑ Pressure
Characteristics of Gases ● Celsius to Kelvin: K = C + 273.15
● Gases exhibit fluidity and have measurable flow rate, ● Kelvin to Celsius: C = K - 273.15
volume, and pressure. ● At 0 Kelvin (absolute zero), its particles would b
● According to fluid mechanics, gases and their particles stationary, and the gas would cease to exist in its gaseou
can be considered fluids. state, instead becoming a solid or liquid depending on th
● No fixed shape or volume––gases take the shape and substance.
volume of their container. 𝑃1 𝑃2 𝑃
● Gas particles move freely and rapidly in random motion.
𝑃α𝑇 | 𝑇1
= 𝑇2
| 𝑇
=𝑘
● Gases are compressible and expand to fill any available Ideal Gas: Theoretical gas composed of many random
space. moving point particles that do not experience interpartic
Kinetic Molecular Theory (KMT): A model used to explain gas interactions.
behavior accurately. It consists of five postulates: ● No interparticle forces: No attractive or repulsiv
1. Constant Motion – particles move in straight lines interactions.
randomly. ● Does not condense: Remains a gas even at lo
2. Negligible Volume – the size of gas particles is tiny temperatures.
relative to the space between them. ● Particles have no volume: The only volume considered
3. Elastic Collisions – no loss of kinetic energy during that of the container.
collisions. Aspect Ideal Gas Real Gas
4. Pressure – caused by collisions of particles with Intermolecular Present (attractive
None
container walls. Forces & repulsive)
5. Kinetic Energy – directly proportional to temperature Particle Volume Negligible Finite
(in Kelvin). Can condense at
Additional Assumptions: Condensation Does not condense
low temperatures
● Gas particles experience negligible intermolecular forces Deviates at high
(no attraction or repulsion). Obey Ideal Gas Law
Behavior pressure & low
● Gravitational and electromagnetic forces between gas perfectly
temperature
particles are ignored.
Gas Unit Conversions Ideal Gas Law: States that under the same temperatur
● 1 kP: 1,000 Pa pressure, and volume, all gases contain the same number
● 1 atm: 101.325 kPa : 101,325 Pa molecules but not the same mass.
● 1 Bar: 0.987 atm : 100 kPa : 100,000 Pa
𝑃𝑉 = 𝑛𝑅𝑇
● 1 Torr: 0.00131579 atm : 133.322 Pa
● P – Pressure
Lorenzo Romano Amedeo Carlo Avogadro
● V – Volume
Avogadro's Number (6.02 × 10²³): A fundamental constant in
● n – no. of moles
chemistry. Represents the number of particles (atoms,
● R – Proportionality Constant
molecules, ions, etc.) in one mole of a substance.
● T – Temperature
♡ Avogadro’s Law | Direct: Equal volumes of gases at the
Proportionality Constant (k/R): Fixed value that relates tw
same T and P contain the same number of molecules (n).
variables in a gas law equation. It ensures the mathematic
↑ Volume = ↑ Moles
relationship between gas properties remains consistent.
𝑉1 𝑉2 𝑉
𝑉α𝑛 | 𝑛1 = 𝑛2 | 𝑛 = 𝑘 Value of R Units Used When…
Sir Robert Boyle, FRS Used in
Boyle's Law | Inverse: Volume is inversely proportional to energy-related
pressure if the temperature is constant. calculations,
↑ Pressure = ↓ Volume Joules per mole including
8.314 J/(mol·K)
per Kelvin thermodynamics,
1 kinetic energy, and
𝑃α 𝑉 | 𝑃1𝑉1 = 𝑃2𝑉2| 𝑃𝑉 = 𝑘 work involving
Jacques Charles gases.
Charles' Law | Direct: Volume is directly proportional to Used when
absolute temperature if the pressure remains constant. pressure is in
↑ Temperature = ↑ Volume atmospheres (atm
𝑉1 𝑉2 𝑉 0.0821 Liters · atmosphere and volume is in
𝑉α𝑇 | 𝑇1 = 𝑇2 | 𝑇 = 𝑘 L·atm/(mol·K) per mole per Kelvin liters (L). Common
When the temperature of a gas sample increases: in chemistry and
● Gas particles move faster. general gas law
● Collisions with the container walls become more frequent. problems.
● Each collision exerts a greater force due to increased
kinetic energy.
● To maintain constant pressure, the gas must expand and
occupy a larger volume, reducing the frequency of
collisions per unit area.
