States Of Matter Gases And Liquids L-4
States of matter
States Of Matter Gases And Liquids L-4
Recap
- Intermolecular interactions
- Properties of gases
- 11 elements in the periodic table that are naturally present as gases
States Of Matter Gases And Liquids L-4
Recap
- Little intermolecular interactions (ideal system)
- Atmosphere (gas)
- Environmental - reaction in gas phase
- Classic experiments
States Of Matter Gases And Liquids L-4
Robert Boyle's experiment
- In 1862 Robert Boyle gave the relation between P and V of a fixed mass of gas at constant T
- Robert hooke was his assistant
States Of Matter Gases And Liquids L-4
Robert Boyle's experiment
- Torricelli - mercury manometer
States Of Matter Gases And Liquids L-4
Robert Boyle's experiment
| Number of spaces in the short leg of the manometer tube |
(h) Height different between the two Hg level |
h+29.1 inches |
| 48 |
0.0 |
29.1 inches |
States Of Matter Gases And Liquids L-4
Mercury manometer
| Number of spaces in the short leg of the manometer tube |
Height different between the two Hg level |
h+29.1 inches |
| 48 |
0.0 |
29.1 in |
| 44 |
2.8 |
31.9 in |
| 40 |
6.2 |
35.3 |
| 36 |
10.1 |
39.2 |
| 32 |
15.1 |
44.2 |
| 28 |
21.2 |
50.3 |
States Of Matter Gases And Liquids L-4
Mercury manometer
- V versus P1 plot
States Of Matter Gases And Liquids L-4
V versus graph
- PV=K→ temperature mass of gas
- V∝p1
States Of Matter Gases And Liquids L-4
Volume on temperature
- Jacques Charles (1790)
- Joseph Gay - Lussac (1802)
- Fixed mass and constant of P
- V1 immersed in ice - 0∘C
- V2 immersed in boiling rate - 100∘C
States Of Matter Gases And Liquids L-4
Charles law
- ΔV∝ΔT(Charles Law)
- ΔV=k′ΔT
- V1V2 at 0∘C at 100∘C=1.375
- This is independent of gas
- For a fixed amount of gas this ratioworks out to be 1.366
States Of Matter Gases And Liquids L-4
Plot of volume versus temperature
- K=oC+273.15
States Of Matter Gases And Liquids L-4
Units of volume
- SI→m3
- dm3/1dm=0.1m
- 1dm3=10−3m3
- Liter ≡1000cm3
- 100cm≡1m
- mL≡10−3L
States Of Matter Gases And Liquids L-4
Units of pressure
- P=h×d×g
- h = Height of the fluid in the manometer
- d = Density of the fluid
- g = Gravity of earth
- Inches of Hg/cm & Hg/mm of Hg
States Of Matter Gases And Liquids L-4
Units of pressure
- 1 Atmosphere = 760 mm of Hg
- Pascal(Pa) = SI unit of pressure
- P=AF=aream×a= m2kgms−2
- 105 Pa=1 bar
- mm of Hg → atmosphere → Pa → bar
States Of Matter Gases And Liquids L-4
Boyle's law
- Relationship between pressure to volume
- 1.53 L of SO2 gas at a pressure of 5.6×103Pa pressure in changed to 1.5×104Pa. what is the volume occupied by SO2 gas under the new condition ?
States Of Matter Gases And Liquids L-4
Boyle's law
- Solution
- P1=5.6×103PaV1=1.53L
- P2=1.5×104PaV2= ?
- P∝V1 or V∝P1
- P1V1=P2 V2P1P2=V2V1
- V2=P2P1V1
States Of Matter Gases And Liquids L-4
Example of Charles law
A sample of gas at 15oC and 1 atmospheric pressure has a volume of 2.58L what volume will this gas occupy at 38oC and 1 atmospheric ?
Solution
T1 = (273.15+15)K
T2 = (273.15+38)K
V1 = 2.58 {L}
V ∝ T
T1V1=T2V2
288.15K2.58L=311.15KV2(L)
States Of Matter Gases And Liquids L-4
Example of charles law
- Solution
- V2(L)=288⋅15k311⋅15K×2⋅58 L
- Good practices - keep the units when you do the algebraic manipulation
States Of Matter Gases And Liquids L-4
Avogadro's hypothesis
- Gay-lussac - when gases react , volumes are in small ratios
- Avogadro - equal volumes of all gases at constant T & P contain equal number of molecules
States Of Matter Gases And Liquids L-4
Avogadro's hypothesis
- Cannizzaro (1862) - avogadro's hypothesis
- Dalton - atomic hypothesis atoms - same mass
- Mass of a gas = N×m
- N2+3H2→2NH3
States Of Matter Gases And Liquids L-4
Three gas laws
- V∝P1( Boyle )
- V∝T (Charles and Gay-Lussac)
- V∝n (Avogadro hypothesis)
States Of Matter Gases And Liquids L-4
Practical use
- Cars→air bags
- Air bags of volume 36L with N2 gas at 1.15 atm and 26oC
- NaN3(s)→N2(g)
- How much of NaN3(s) must be decomposed to get N2 gas at 1.15 atm ? & 26oC to occupy 36L ?
- NaN3(s)→very little volume
- N2(g)→lot more volume
States Of Matter Gases And Liquids L-4
Ideal gas equation of state
- V∝T
- V∝P1
- V∝n
- PV = nRT
States Of Matter Gases And Liquids L-4
Thank you
States Of Matter Gases And Liquids L-4 States of matter $\rightarrow$ $\rightarrow$ States of matter $\rightarrow$ $\rightarrow$ Recap
