Gaseous State

Question 1

Kinetic Theory of Gases

Answer 1

1. The gas particles are of negligible size and occupy negligible volume compare to the volume of the contain
2. The gas particles have negligible IMFOA
3. Collisions between gas particles are perfectly elastic
4. The gas particles are in continuous, rapid, random and linear motion
5. The average kinetic energy of gas particles is proportional to the temperature on the kelvin scale

Question 2

Real gases behave most ideally under?

Answer 2

1. High temperature
   Gas particles have very high kinetic energies and can overcome IMFOA
2. Low pressure
   The gas particles are far apart and thus occupy negligible volume compared to the volume of the container. Also the IMFOA between the gas particles are negligible

Question 3

Maxwell-Boltzmann Distribution

Answer 3

Graph of number of particles with a given energy (y-axis) against energy (x-axis)

Question 4

Ideal gas equation

Answer 4

pV = nRT

p = pressure in Pa
V = volume in m³/10dm³
R = molar gas constant, 8.31 JK^-1mol^-1
n = amount in mol
T = temperature in K

Question 5

Boyle’s Law

Answer 5

For a fixed mass of gas at a constant T, P is inversely proportional to V

P = k/V

P₁V₁ = P₂V₂

Question 6

Charles’ Law

Answer 6

For a fixed mass of gas at a constant P, V is directly proportional to its T in K

V = kT

V₁/T₁ = V₂/T₂

Question 7

Gay-Lussac’s Law

Answer 7

For a fixed mass of gas at constant V, its P is directly proportional to T in K

P = kT

P₁/T₁ = P₂/T₂

Question 8

Avogadro’s Law

Answer 8

At the same T and P, equal V of any gas contain the same number of particles

Question 9

Dalton’s Law of Partial Pressure

Answer 9

Total pressure of a mixture of Gases is equal to the sum of the partial pressures of each component gas

P_T = P₁ + P₂ + …

Question 10

Partial pressure

Answer 10

The partial pressure of each gas in a mixture is the pressure the gas would exert if it alone occupied the whole container at same T and P

Question 11

Real gases deviations from ideality

Answer 11

1. Gas particles have significant volume compared to the volume of the container
2. There are significant IMFOA between the gas particles

Question 12

Effect of moderately high pressures on real gases (up to 400 atm)

Answer 12

pV/RT lower than ideal (< 1) due to significant IMFOA

• Molecules that are about to strike the walls
  of the container experience IMFOA
• Reducing impact on walls
• Pressure decreases

Question 13

Effect of very high pressures on real gases (above 400 atm)

Answer 13

pv/RT greater than ideal (> 1) due to significant molecular volume

• Molecules pushed too close
• Occupy significant V compared to container
  V
• Hence gas is less compressible
• V greater than ideal

Question 14

Effect of low temperatures on real gases

Answer 14

pV/RT < 1

• Gas molecules low KE
• Cannot overcome IMFOA
• Molecules striking wall experiences IMFOA
• Reducing impact
• P lower than ideal