# Shared Flashcard Set

## Details

gas laws
test questions
71
Physics
11/12/2007

Term
 pressure is measured in?
Definition
 pascals
Term
 volume is measured in?
Definition
 liters
Term
 temperature measured in?
Definition
 Kelvin=Celcius + 273
Term
 what generates pressure?
Definition
 particles bombarding a container wall (think of particles hitting against a cylinder wall)
Term
 what is molecular theory?
Definition
 inside a lattice chain of a solid there is a "static" state, but when heat is added the vibrations and excitement of the molecules increase. as heat is added, solids change statesto liquids and then to gases.
Term
 what are Van de Wealts Forces?
Definition
 the increasing movement and forces of molecules that are related to an increase in heat.
Term
 what is an ideal gas?
Definition
 a perfect gas-but only in theory. a hypothetical gas. consists of identicle particles of zero volume and no intermolecular forces. +molecules undergo perfectly elastic collisons with walls+molecules are far apart+real gasses do not exibit these exact properties.+this approximation model breaks down at high pressure and low temperatures where intermolecular forces play a greater role related to gas properties.
Term
 what  is Boyle's Law?
Definition
 1st ideal gas law.    Temperature is constant! pressure is inversely proportional  to volume. equation:  pV=K  or  P1V1=P2V2
Term
 What is Charles' Law?
Definition
 2nd ideal gas law. Pressure is constant. volume is directly proportional to temperature. equation: V/T= P so V1/T1= V2/T2
Term
 1 ATM IS EQUAL TO:
Definition
 760 mmhg, 100Kpa, 100,000 p, 14.7 psi
Term
 what is Gay Lussac's Law?
Definition
 3rd ideal gas law. volume is constant. pressure is directly proportional to temperature. equation: P/T=K or V  so  P1/T1 = P2/T2 +MUST USE kELVIN WHEN DOING TEMP GAS EQUATIONS
Term
 WHAT IS THE COMBINED GAS LAW?
Definition
 It combines Charles', Boyles, and GayLussac's Laws.Changes in pressure, volume, or temp. can be found mathemtically. It states that the product of a gasses volume and its pressure over temperature is equal to a constant.  P1V1/T1 = P2V2/T2
Term
 What is Avogadro's Hypothesis or Law?
Definition
 equal volumes of gases, at the same temp and pressure, contain the same number of particles or molucules. +the ideal gas constant has the same value for all the gases. one mole of gas occupies 22.4 Liters. or molar volume. Avogadro's number= 6.022 x 1023 particles per mole
Term
 Avogadro's law and the combined gas law make the ideal Gas Law.What is the equation and its components?
Definition
 equation:  pv=nRtp=pressure   1 atm= 100Kpa, 100,000 pa or 760 mmhgv=volume    1000L = m3n=#of molesR=gas constant 0.0821 (L, atm, mol, K) or 8.314472 (m3,pa, K, mol)t=temp in Kelvin (9C= 5F-160) most acurate for monatomic gases.+favored at high temps and low pressures.
Term
 What is Dalton's Law?
Definition
 also called Dalton's Law of Partial Pressures. states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressure of each individual component in a gas mixture. It assumes that the gases do not react with each other.
Term
 critical temperature
Definition
 Temperature above which asubstance cannot be liquefied nomatter how much pressure is applied. Especially important for N2O. Critical temperature for Nitrous is 36.5°c .
Term
Definition
 Adiabatic heating and cooling are processes thatcommonly occur due to a change in the pressureof a gas.�� Adiabatic heating occurs when the pressure of a gas is increased. An example of this is what goeson in a bicycle pump.�� i.e. - bicycle pump to inflate a pneumatic tire the barrel of the pump is found to have heated up as a result ofadiabatic heating.�� Adiabatic cooling occurs when the pressure of a gas is decreased, such as when it expands into alarger volume.�� i.e. - when the air is released from a pneumatic tire; the outlet air will be noticeably cooler than the tire, and afterall the air has escaped the valve stem will be cold to thetouch.
Term
 What is the Joule Thompson effect?
Definition
 an example of adiabatic cooling.Gas from a high pressure cylinder is allowed to escape into space. As the gas expands, it cools adiabatically.
Term
 What is a cryoprobe and how does it work?
Definition
 An example of adiabatic coolong and the joule Thompson effect.A small tube is attatched to a pressure source, as the gas escapes, it cools an area rapidly.
Term
 What is in Nitrous Oxide Cylinders?
Definition
 liquid and gas due to the critical temp of N2O.
Term
 What happens in Nitrous oxide Cylinders?
Definition
 pressure is constant in cylinder until the liquid disappears then the pressure decreases linearly as the cylinder empties.
Term
 temp drop may cause moderate decrease in pressure in cylinders due to what 2 things?
Definition
 latent heat evaporation (occurs as liquid vapoizes in the atm as it cools)and Joule thompson effect-cools the cylinder as gas escapes
Term
 Gas cylinder Specs:
Definition
 Gas           color             psi            liters      oxygen       green         2,200           660 nitrous       blue            745             1590 air             yellow         1900             625
Term
 oxygen and nitrous oxidedifferences when emptying
Definition
 Pressure in the nitrous cylinder is steady until the liquid is gone then drops exponentially. oxygen pressure drops at a steady rate.
Term
 At what pressure and amt of liters will all the liquid of nitrous oxide be gone and the pressure drop off linearly?
Definition
 745 psi and 400 liters
Term
 describe the difference between O2 and N2O when emptying the cylinders?
Definition
 with O2, the pressure drops as the amt of O2 declines. With N2O, the pressure remains the same until the tank has 400 liters.
Term
 what is an exponential function?
Definition
 a special form of non-linear change encountered in nature. (dependent upon natural process that we see daily)
Term
 what is an exponential process?
Definition
 rate of change of a quantity at any time is proportional to the qua ity at that time. ++as the quantity changes-it effects the rate of change.
Term
 exponential function and process equation?
Definition
 y = mx + by=vertical axis or volumem=slope of the lie on the graftx=horizontal axis or timeb=constant that you can add to the baseline toincrease or decrease.
Term
 example of an exponential process.
Definition
 flow is proportional to pressure, and pressure is proportional to volume, therefore flow is proportional to the volume at the time. Q∞P, P∞V, therefore Q∞V
Term
 SWhat types of things in anesthesia would apply the washout curve?
Definition
 +basis of dye dilution technique+thermo dilution technique+used to measure cardiac output+measures concentrations of drugs+nitrogen washout curve
Term
 What is the dye washout curve and what does it test?
Definition
 cardiac output=dose of dye injected/area under the curve. concentration of dye=vertical axistime=horizontal axisthe concentration peaks, then goes down and peaks again. presumably because the dye does not clear the blood stream in one cycle. (big hill, then little hill)
Term
 What two alternativemethods developed to track the exponential process?
Definition
 half life and time constant
Term
 What is half life and what is it useful for?
Definition
 time it takes the quantity to reach 50%.useful in radioactvity measurements.
Term
 What is the time constant and what is it used for?
Definition
 time it takes for the process to end assuming the first rate of change continues. The processis linear;where the linear line is and come back up to the curve-this is where pt has one time constant. Tau
Term
 equation for time constant?
Definition
 time constant x 0.693 = half life69% of drug cleared
Term
 What is the time constant for the lungs and the equation?
Definition
 time constant = C x R (C is compliance and R is resistance) Compliance should remain the constant.
Term
 time constant formula for a washout curve?
Definition
 T (time constant) = volume undergoing washout/flow of perfusing fluid
Term
 exponential formula for the lung?
Definition
 when K = 2.718 it is given the symbol é Vt=Vo (2.718) -t/cr or Voe -t/cr
Term
 Positive exponential processes.
Definition
 positive exponential-ie bacterial growth upwards slopebuild up exponential-looks like a hill
Term
 what is solubility?
Definition
 the ability of a solute to dissolve in a solvent. a saturated solution is when the maximum amt of solute has been dissolved.
Term
 Henry's law
Definition
 at a particular temp the amt of a given gas dissolves in a given liquid is directly proportional to the partial pressure of the gas in equilibrium with the liquid.
Term
 Henry's law applied to scuba divers.
Definition
 -at depth the body absorbs nitrogen-ascend too quickly and it comes out of the solution and in the joints and tissues. "THE BENDS"+++Henry's law only applis for constant temperatures.
Term
 What is Cason's disease?
Definition
 The Bends!
Term
 The solubility of a gas is dependent upon what?
Definition
 temperature, gas, liquuid, and partial pressure.Understand that different gases dissolve differently and different liquids can effect the how a gas dissolves.
Term
 What are the two solubility coefficients?
Definition
 Bunsen solubility coeffiecient (not r/t anesthesia) and oswald solubility- it is the V of a gas which dissolves in 1 unit of liquid at the temp concerned. (PRESSURE INDEPENDENT!)
Term
 When temp increases gases dissolve ________?
Definition
 less
Term
 compare solubility of N2 and Nitrous at same pressure and temp?
Definition
 N2 dissolves at the rate of 0.014L,N2O dissolves at the rate of O.39L
Term
 What are partial coefficients?
Definition
 the ratio of the amt of substance present in one phase compared with another, the two phases being of equal volume and equilibrium. +temp and phase must be specified+applied to 2 liquids
Term
 Solubility and uptake of anesthetics
Definition
 ether is more soluble in blood (12) than nitrous (.47) or halothane (2.3)
Term
 How do gases that are soluble in blood effect anesthesia?
Definition
 gases that are more soluble in blood are less effective in anesthesia, insoluble gases have their effect on the brain more quickly.
Term
 second gas effect
Definition
 the second gas makes the gradient steeper which helps for absorption of other gas during inspiration, but during expiration the gas comes outmore quickly than oxygen and the gradient can cause hypoxemia.
Term
 Oil solubility and anesthetic potency.
Definition
 Fat(neurons/brain) is analogous to oil.Oil Gas partition coefficient means more soluble=more potent.
Term
 application of Henry's Law.know that O2dissolves in blood at 0.003cc/100cc/mmHg partial pressure.know that CO2dissolves at   0.067/100cc/mmHg partial pressure
Definition
 When PaO2 is 300mmHg, how much is dissoled in the blood?O2=300mmHg x 0.003cc/100cc/mmHg =0.9/100cc bloodCO2= 300mmHg x 0.067/100cc/mmHg= 20.1/100cc blood
Term
 Diffusion definition and example.
Definition
 -process by which the molecules of a substance transfer through a layer or area such as the surface of a solution.-lungs diffuse anesthetic gases-drugs diffuse in liquids ie:spinals
Term
 factors that effect diffusion?
Definition
 molecular size, tension gradient, membrane thickness and area, +concentration gradient effects rate of diffusion
Term
 What is Fick's Law?
Definition
 rate of diffusion of a substance across a unit area is proportional to the concentration gradient.  ↑ gradient = ↑ rate of diffusion
Term
 rate of diffusion affected by
Definition
 concentration gradient and solubility of a gas ie:diffusing into a liquid
Term
 rates of diffusion of gas are different. compare O2 and CO2.
Definition
 more likely to become hypoxemic than hypercarbic.
Term
 Graham's Law
Definition
 diffusion rate = reciprocal of the square root of the molecular weight.
Term
 diffusion equation=proportional to tension gradientproportional to solubilityinversly proportional to membrane thicknessinversely proportional to the √molecular wt.proportional to membrane arealiquids diffuse less rapidly than gases
Definition
 Diffusion= (P1-P2)(area)(solubility)           (Membrane thickness)(√molecular weight)
Term
 Osmosis
Definition
 occurs with a semi-permeable membrane and 2 liquids. larger molecules unable to diffuse through membrane, but smaller molecules go through membrane due to gradient, so that side of the membrane has more pressure, which is called osmotic pressure.
Term
 osmolarity
Definition
 moles per liter
Term
 osmolality
Definition
 moles per kilogram
Term
 oncotic pressure
Definition
 osmotic pressure related to proteins
Term
 components of normal saline
Definition
 Na+, K+, Ca+, lactate, Cl-; total osmolarity=278 mmol/literbody osmolarity=300 mmol/litertherefore almost isotonic solution which has little oncotic pressure.
Term
 increased hydrostatic pressure=
Definition
 cells exploding
Term
 increased oncotic pressure=
Definition
 edema because there is no oncotic pressure to drive fluid back into the veins.
Term
 principle of operation for capillaries.
Definition
 -interstitial fluid has no proteins!-plasma has proteins-capillaries act as semi-permiable membranes(filters proteins)-difference in osmolar gradient called oncotic pressure
Term
 colligative properties=
Definition
 osmotic pressurefreezing point depressionvapor pressure reductionboiling point evaluation
Term
 azeotropes
Definition
 a mixture which vaporizes in the same proportion as its constituent volume proportions ie: alcohol 96% & H2O 4% always evaporate at same rate.(application of Raoult's law)
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