Exam II Flashcards
(105 cards)
What is Solubility?
The maximum amount of one substance (solute) that is able to dissolve into another (solvent).
Factors of Solubility
Intermolecular interactions
Temperature
Pressure
How do intermolecular interactions affect solubility?
“Like-dissolves-like”
Polarity/ionization
Similar electron configuration = higher solubility
How does temperature affect solid/liquid solubility?
Elevated temp = increased solubility
How does pressure affect solubility?
Higher pressure increases solubility (Henry’s Law - gases)
Endothermic Reactions
Reaction that requires/uses energy.
Exothermic Reactions
Reactions that release energy.
Increased temperature reduces solubility.
Effect of Temperature on Gas
Inverse relationship - as temperature increases, solubility decreases.
Henry’s Law
p = kc
The solubility of gas is directly proportional to pressure.
Diffusion
The net movement of one type of molecule through space as a result of random motion intended to minimize concentration gradient.
Ex. Food coloring in water.
Osmosis
The movement of water across a semipermeable membrane to equilibrate a concentration gradient.
Graham’s Law
r = 1/,^mw (square root)
The rate of effusion of a gas is INVERSELY proportional to the square root of its molecular weight.
Small = Faster diffusion
Fick’s Law
Diffusion of gas is DIRECTLY proportional to:
-Partial pressure gradient
-Membrane solubility
-Membrane area
INVERSELY proportional to:
-Membrane thickness
-Molecular weight
Fick’s Law Application to Anesthesia
Passive Oxygenation - ENT cases
Diffusion Hypoxia
Concentration Effect
Second Gas Effect
What is diffusion hypoxia?
Nitrous is very soluble
tissues become saturated, diffuse into alveoli quickly once turned off, creating hypoxic mixture in the lungs <21%
What is concentration effect?
Increasing the fraction of inspired concentration (FI) of an inhalation anesthetic will more rapidly increase the fraction of alveolar concentration (FA) of the agent– think about Henry’s law
What is the second gas effect?
As nitrous is diffused into the blood from the alveoli at a faster rate than the volatile anesthetic, it leaves a void of volume in the alveoli. It creates pressure gradient, allowing more volatile anesthetic to enter the alveoli at a faster rate.
Tonicity
The capacity of a solution to modify the volume of a cell by altering its water content.
Hypotonic
Na concentration <130 mEq/L
Cytolysis = Cells in hypotonic fluid absorb too much water and burst.
Isotonic
Na concentration between 130-155 mEq/L
Hypertonic
Na concentration >155 mEq/L
Plasmolysis = Cells in hypertonic solution lose water and shrink.
What is an acid?
A substance that can donate a proton (H+) or accept an electron pair in a chemical reaction.
What is a base?
A substance that can accept a proton (H+) or donate an electron pair in a chemical reaction.
What is pH?
Measure of acidity or alkalinity of a solution, qualifies, the concentration of H+ ions in a solution.
pH range = 0-14