Gaseous State Flashcards
Formula to use when gas in 1 set of condition.
What to note when using the formula?
PV=nRT
Pressure in Pa, Volume in m^3, Temperature in K (C +273)
3 Variations of PV=nRT
Molar Mass: PV = (m/M)RT
Density: P = (p)(RT/M)
Concentration: P = cRT
Formula to use when a change in conditions
PV/nT = PV/nT
Make R the subject
What is room temperature?
20°C, 293K
What to note when X and Y are ‘connected’?
Increase in volume
Formula for partial pressure of gas A
Pressure A = Ptotal x na/nt
na –> No. of moles of a
nt –> Total no. of moles
Formula for sum of partial pressures (Total pressure)
Ptotal = Pa + Pb + Pc + ….
3 steps when tackling graph questions?
- Identify the Y against X
- Make Y the subject
- Change the constants to k
Recall the 3 types of graphs + one thing to note with graphs with temperature
Refer to image 1 and 2
°C vs K
3 main assumptions of an ideal gas
- Volume of gas molecules negligible compare to volume of container
- Force of attraction between gas molecules/ gas molecules and walls are negligible
- Molecular collisions perfectly elastic, no loss of KE
- Force of attraction between gas molecules/ gas molecules and walls are negligible
2 Conditions for real gas to approach ideal behaviour
- Low pressure
- Gas molecules far apart
- Volume of gas negligible compared to volume of container
- Negligible IMF - High temperature
- Gas molecules faster (Higher KE)
- Negligible IMF
When does negative deviation from ideality occur? What factors affect amount of deviation?
???
Lower pressure.
IMF (id-id,pd-pd,H-bonding), where H bonding highest deviation
id-id –> no. of e-
When does positive deviation from ideality occur? What factors affect amount of deviation?
???
Higher pressure (Lower volume of container)
Molecular volume of gas
