Gases in solution Flashcards
HOw does pressure affect gas solubility
Gas dissolved is directly proportional to the partial pressure of the gas (henrys law)
How does temperature affect gas solubility
Gas dissolved in liquid decreases as temperature increases
Which is more soluble, CO2 or O2
CO2
Which is more soluble, N2O or N2
N20
WHat is the solubility coefficien
Volume of gas that dissolves in a given volume of liquid
WHat is the bunsen coefficient
volume of gas, corrected to Standard Temperature and Pressure (STP), that dissolves in 1 unit volume of the liquid at the temperature concerned, where the partial pressure of the gas above the liquid is 1 atmosphere.
What is the ostwald solubility coefficient
volume of gas that dissolves in one unit volume of liquid at temperature concerned- is independent of pressure provided measured at ambient pressure
WHat is the partition coefficient
ratio of the amount of substance present in equal volume phases of liquid and gas in a closed system at equilibrium at a standard pressure and temperature.
What do partition coefficients allow comparison of?
Solubility of different substances to be compared
What does the blood:gas partition indicate in inhalational anaesthetics?
How soluble it is in blood and the rate of onsetW
What does the oil gas partition coefficient indicate
HOw soluble in oil and relates to the potency of the agent
How is the blood gas coefficient related to speed of onset
Higher blood gas coefficicent = longer to reach equilibrium=slower speed of onset
Order volatiles by high speed of onset to low (low blood: gas to high blood:gas)
Desflurane -> sevo_> iso-> halothane
HOw does oil:gas coeffient relate to potency?
Higher the coefficent the more potent the agent
WHat is the relationship between oil:gas coeff. to potency known as
Meyer overton hypotehsis- graph plots an inverse relationship between solubility and MAC (which is the inverse of potency)
