TOPIC 4: THE GASEOUS STATE Flashcards
Intermolecular forces of attraction between gases and liquid
IMFA of gases is MUCH weaker
Eqn connecting Volume & Pressure
V ∝ 1/p
pV = k
p1V1 = p2V2
Eqn connecting Volume & Temperature
V ∝ T
V/T = k
V1/T1 = V2/T2
Eqn connecting Volume & Amt of Gas
V ∝ n
V/n = k
V1/n1 = V2/n2
Ideal Gas Equation
pV = nRT
*R is the molar gas constant (8.31 JK⁻¹mol⁻¹)
Dalton’s Law of Partial Pressures
In a mixture of gases that do not react with one another, each gas behaves as if it was the only gas present
Equation for Partial Pressures
ptotal = pA + pB + pC + ….
Mole Fraction
χ = amt of A / total amt of all components in mixture
4 Assumptions of the Kinetic Molecular Theory of Gases
- The volume of gas particles is negligible compared to the total volume occupied by the gas
- There are no forces of attraction between the gas particles.
- When the particles collide, the collisions are perfectly elastic.
- The particles are in constant random motion.
When does real gas deviate the LEAST from ideal gas
Low pressure, High temperature
Effect of Pressure on p-pV graph (2 parts)
pV decreases with increasing p
* Intermolecular forces of attraction are significant
* When a molecule is about to strike the wall of the container, it is attracted by particles surrounding it
* Particle slows down and hits wall with a smaller force
* Pressure exerted is lower, so pV is lower
* AS P INCREASES, particles closer together
* IMFA more significant
* pV decreases with increasing p
pV increases with increasing p
* Volume of gas particles are significant
* So, volume of gas occupied by a real gas is larger, pV higher
* As P INCREASES, volume of container decreases
* Volume of gas particles compared to container becomes MORE significant
* pV increases with increasing p
Effect of high temperature
- Kinetic energy of gas particles increase
- IMFA between particles become insignificant
- No. of collisions and force per collision increase
- Less deviation from ideality
