Gas Laws Flashcards
Henry’s Law
- the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas
Application of Henry’s Law
- Using the partial pressure of O2 or CO2 to find out how much O2 and CO2 is dissolved in blood.
- multiple the PaO2 and PaCO2 by the coefficient to find Solubility
- increasing FiO2
- over-pressuring the vaporizer
Solubility coefficient for oxygen
0.003
Solubility coefficient of CO2
0.067
Graham’s Law
- The rate a molecule diffuses at is inversely related the square root of its molecular weight
- smaller molecules diffuse faster
Application of Graham’s Law
-Nitrous oxide diffusing into air filled cavities
(nitrous diffusing into endotracheal tube cuffs)
-apneic oxygenation
(The continual diffusion of oxygen in the blood strictly from concentration gradient from the ventilator circuit into the alveoli)
Fick’s Law
- The rate of diffusion of a gas across a semipermeable tissue is related to :
1) partial pressure of the gas (directly related)
2) the membrane solubility of the gas (directly related)
3) the area of the membrane (directly related)
4) membrane thickness (indirectly related)
5) molecular weight (indirectly related)
Application of Fick’s Law
-2nd gas effect of nitrous oxide
Pressure Equivalents
1atm = 1bar = 760 mmHg = 760 torr = 14.7 psi = 1020 cm H2O = 100KpA
Boyles Law
P1 * V1 = P2 * V2
Example of Boyle’s Law
- ventilating with reservoir bag
- spontaneous breathing
- bellows on vent
Charles Law
V1/T1 = V2/T2
Application of Charles Law
-
Guy Lussac’s Law
P1/T1 = P2/T2
Application of Guy Lussac’s Law
-Gas leaving the E-cylinder creates a frost on the outside of it
Universal gas law
PV = nRT
Application of Universal Gas Law
- as an e-cylinder of a tank empties, the pressure decreases
Avogadro #
6.02 E23
1 mole of any substance occupies how much space in L
22.4L
Avogadro’s Law
V1/n1 = V2/n2