5.8 gaseous state

Question 1

conversion of atm, bar, cm3, dm3 and celcius

Answer 1

1 atm: 101325 Pa
1 bar: 10^5 Pa
1 cm3: 10^-6 m3
1dm3: 10^-3 m3
1 celcius: 273 + 1 kelvin

Question 2

partial pressure formula

Answer 2

Pa = (Na / Nt) Pt

Question 3

ideal gas equation

Answer 3

pV = nRT, (R = 8.31, p in Pa, V in m3, T in K)

Question 4

what are the 4 behaviours of ideal gas?

Answer 4

1) gas particles have negligible volume compared to the container
2) there are no intermolecular forces of attraction between gas particles
3) collisions between the gas particles and container are perfectly elastic
4) gas particles are in constant, random motion

Question 5

what are the ideal conditions for gas to be closest to ideal and why?

Answer 5

• low pressure: volume of gas particles is negligible to that of the container
• high temperature: negligible intermolecular forces of attraction between gas particles

Question 6

explain the shapes of the graphs of NH3, O2 and H2 compressibility factor`

Answer 6

• the hydrogen bonding between NH3 molecules are stronger than the id-id interactiions between O2 molecules. this implies that NH3 has a larger deviation from ideal gas behaviour than O2, hence curve exhibits a greater dip
• id-id between H2 molecules in the weakest due to smallest electron cloud size. this implies that it would behave close to an ideal gas, hence does not exhibit a dip