Chemistry & Physics Flashcards
3 elements that compose over 97% of the human body?
hydrogen 63%
oxygen 24%
carbon 11 %
weakest intermolecular force that results in lower boiling points and higher SVPs?
london dispersion
How much volume does 1 mole of hydrogen occupy at 0 degrees C and 1 atm?
22.4 L
Volatile anesthetics are fluorinated to reduce:
toxicity
flammability
time to recovery after administration
Law that describes what happens to a helium balloon when you take it out in the cold and it shrinks?
Charles Law
law that describes the sudden hypoxia that can ensue after discontinuing nitrous oxide?
Fick’s law of diffusion
law that is the basis for the mechanism of air-O2 dilution that occurs in the Venturi mask?
Bernoulli’s Principle
Which physics laws explain why patients may desaturate quickly when you turn off nitrous oxide? (2)
Graham’s law
Fick’s Law of diffusion
Atomic Properties: The number of ____ in an atom distinguishes that element from others & ____ determines its reactivity.
Protons
Electrons
Octet Rule & Reactivity of electrons in atoms
Atoms are more stable with 8 electrons in the outer shell. Electrons in the outermost shell are called valence electrons.
Electrons on the higher energy levels / outer levels require less energy to be removed in an atom, so those electrons are most likely to be involved in reactions
Atoms will work to obtain 8 in their outer shell by 1) ionizing or 2) sharing electrons with other atoms… both lead to bonding with other atoms to form molecules
2 major types of bonds
Ionic
Covalent
Ions
Electrons are gained or lost.
Atoms fill their outer shells by completely acquiring or losing electrons and in doing so become ionized (cations, anions)
Covalent Bonds
The physical sharing of electrons
Sharing of electrons between atoms
Single Bonds, Double Bonds, Triple Bonds
Often involves Carbon
Are stronger than electrostatic bonds
Ionic (Electrostatic) Bonds
Bonds made by the attraction of electrons between atoms
- ion-to-ion interactions [strong] ex: Na+ Cl- become NaCl
- ion-to-dipole interactions [weaker] ex: Na and Cl ions bond to water molecules
- dipole-to-dipole interactions [weakest] ex: water molecules forms weak bonds with one another (surface tension)
Induced dipoles
momentary uneven spatial distribution of electrons, may lead to weak bonding between usually nonpolar molecules
What are London Dispersion Forces?
induced dipole bonding
weakest of all molecular bonds
What are Hydrocarbons?
molecules made up of entirely C & H atoms
Saturated = alkanes
(all available C sites are occupied by a H)
Unsaturated
double-bonded = alkenes
triple-bonded = alkynes
(bonds between the Carbon atoms)
The functional group of Volatile Anesthetics?
methyl ethyl ethers
The functional groups of local anesthetics
amino-esters
amino-amides
*diff functional groups mean different properties (such as metabolism)
Substances that have greater intermolecular forces have:
- greater surface tension
- lower saturated vapor pressures
- higher boiling points
- higher melting temperatures
- lower freezing points
Gas solubility, temperature, and kinetic energy
- inversely related to temperature… as temp increases, less gas is able to dissolve into a liquid
- increased temp represents increased kinetic energy that allows dissolved gas molecules to escape
- lower temp slows the kinetic energy of gas allowing them to dissolve into liquids
Gas solubility in a liquid is directly proportional to _____, as described by Henry’s Law
pressure
-increasing the partial pressure of a gas above a liquid will increase the amount of gas that dissolves in the liquid
Isomers are
isomers are molecules with the same chemical formula but their atoms differ in position
enantiomers = mirror images, cannot be superimposed, have similar chemical and physical properties. this is what “racemic mixtures” are
Fick’s Law of Diffusion: 5 factors of diffusion of a gas through a membrane:
directly proportional to diffusion
1) concentration gradient
2) tissue area
3) gas/tissue solubility
inversely proportional to diffusion:
4) membrane thickness
5) molecular weight
Standard atmosphere pressure
1 atm = 760 mm Hg
the volume of 1 mole of any gas at 0 C
22.4 L
Absolute Zero
(0K or −273.15C) is void of all energy.
Temperature Conversions
C to F = 1.8C + 32 = F
F to C = (F-32) x (5/9) = C
C to K = C + 273 = K
Charles’ Law
Constant: Pressure
V1/T1 = V2/T2
Boyle’s Law
Constant: Temperature
P1V1 = P2V2
Gay-Lussac’s Law
Constant: Volume
P1/T1 = P2/T2
Flow through tubes
Poiseuile’s law is analogous to Ohm’s law
Flow is directly related to the pressure drop (gradient) across the system and is inversely related to resistance
F = (P1-P2)/R
Poiseuille Law and flow through a tube
- the radius of the tube will have the most dramatic effect on flow
Laminar Flow:
F = (πr⁴∆P)/(8∗η∗l)
F = rate of blood flow ∆P = pressure difference r = radius l = length η = viscosity
Velocity
distance/time
ex: cm/sec
Flow rate
volume/time
ex: ml/min
Laminar flow and viscosity
laminar flow the velocity difference between layers depends on the ease with which the layers slide on one another or the viscosity of the fluid
Flow passing through a narrowing is described by what Law of Physics?
Bernoulli’s Principle
As flow passes through a narrowing in a tube, the velocity of that flow increases, and there is a corresponding decrease in pressure at the area of narrowing
- the same that goes in must come out, so where the diameter is smaller the flow must increase
- narrowing also leads to turbulance
Critical Velocity
velocity above which flow changes from laminar to turbulent
Reynolds number > 2000 indicates turbulent flow
Turbulent flow is promoted by? (3 things)
- low viscosity
- large tube diameter
- high density (mass/volume)
Turbulent flow depends on _____ and Laminar flow depends on ______. (viscosity/density)
Turbulent = density Laminar = viscosity
Venturi Effect
Utilizes the pressure drop across a narrowing in a tube. By placing an orifice at the narrowed region of flow where the pressure is lower, fluid or air is allowed to be entrained and enter the flow. It creates an injector. Fluid/Air may be entrained into a flow of liquid or gas.
Coanda effect
The tendency of fluid flow to does not return to its original path after flowing through a constriction or around a curved surface
