Gas Laws and Gas Transfer Flashcards
Define Pressure. What are its units?
Force applied on a containers walls per unit area (P = F/A)
Units = Pascal (Pa)
What is Boyle’s Law?
Pressure inversely proportional to volume (when temp and amount of gas is constant)
What is Charles’ Law?
Volume is directly proportional to temp (on absolute temp scale if pressure and amount of gas is constant)
T1/V1 = T2/V2
What is the Universal/Ideal Gas Law?
Pressure and volume are both proportional to temp
PV = nRT
(n = number of moles of gasp, R = constant (8.314), T = temp (kelvin))
When non-reactive gases mix, molecules of each type still behave…
Independently
What is Dalton’s Law?
The total pressure exerted by the mixture of non-reactive gases is equal to the sum of the partial pressures of individual gases
At point of contact between water molecules and adjacent gas, what happens?
Water molecules evaporate and gas molecules dissolve but there is NO chemical reaction between them.
Equilibrium is reached when partial pressures of each substance on either side of interface are equal
What is the saturated vapour pressure? What changes it?
SVP = equilibrium pressure for water vapour
Depends on temp
Temp at which SVP = atmospheric pressure is the boiling point
What is Henry’s Law?
At a constant temp, physical amount of gas dissolving in a solvent is directly proportional to pressure of gas at the solvent’s surface
Define Solubility.
What does solubility depend on?
Solubility = amount of solute per amount of solvent (measured at saturation conc where adding further solute results in its precipitation
Depends on: ability to dissolve, physical properties of gas/liquid, temp, pressure, pH
Gas molecules that enter water exert…
Tension
What does gas tension indicate?
How readily gas will leave liquid (measure of pressure, kPa)
What does gas exchange in the lung require?
- Very large surface area
- Large blood supply
- High number of small compartments (alveoli)
- Thin membranes
What barriers does oxygen pass through to reach Hb from the atmosphere?
- Diffusion through gas to alveolar wall
- Epithelial cell of alveolus
- Tissue fluid + connective tissue
- Endothelial cell of capillary
- Plasma
- RBC membrane + cytoplasm
What factors is diffusion dependent on?
- Solubility
- Surface Area
- Surface thickness
- Partial pressure
- Distance
- Molecular weight
