Chapter 6 Flashcards
Gas laws
Volume & Pressure are
Inversely proportional
Volume & Temperature are
Directly Proportional
The volume of gas is directly proportional to
The number of moles
Boyle’s Law explains the relationship between
Volume & pressure
In Boyle’s Law, as the pressure increases,
The volume decreases & vice versa
At a higher pressure, gas is more
Concentrated & vice versa
Charle’s Law explains the relationship between
Volume & temperature
With Charle’s Law, volume of a gas is
Proportional to its absolute temperature, as long as the pressure 7 amount of gas are held constant
What is Boyle’s Law equation?
P1V1=P2V2
What is the equation for Charle’s Law?
V1/T1=V2/T2
With Charle’s Law, temperature must be expressed in
Kelvin
How else can you write Charles’s Law?
V=mT
Avogadro’s Law explains
The relationship between Volume & Mole
At equal temperatures & pressures, equal volumes of gas
Contain equal numbers of particles
With Advogadro’s number, the volume of a gas is
Directly proportional to the number of gas molecules, as long as temperature & pressure are held constant
What is the Combined Gas Law
P1V1/n1T1=
P2V2/n2T2
For gases & only for gases, the volume
Percent of each component is always equal to the mole percent
What is the equation for ideal gas law?
PV=nRT
P=pressure
V=volume
n=moles
T=absolute temperature
R=constant
Ideal gas does
Not exist
Volume is inversely proportional to ________ & directly proportional to_______
Pressure; Absolute temperature & to Moles
The standard temperature= is
Exactly 0 degree Celsius
The standard pressure is
1 bar or 100kPa
1 atm=
101.325 kPa=760 torr
What is the standard molar volume of a gas?
Is the volume that exactly 1 mole of an ideal gas occupied under STP conditions
22.71 L
R is called the
Universal gas constant because it appears in several seemingly unrelated physical relationship
The density of a gas depends very strongly on the
Temperature & pressure
Dalton’s Law states the
Total pressure of a gaseous mixture is the sum of the partial pressures of each of the component gases
The partial pressure of a gas in a mixture is the
Pressure the gas would exert by itself under identical conditions of temperature & volume
The partial pressure of each component is
Proportional to the moles of that component in the sample
The partial pressure of each component in a
Gaseous mixture is equal to the mole fraction of the component times the total pressure
Relative humidity measures
The saturation of water in the air
How do you calculate relative humidity?
Concentration of water in the air sample/solubility of water in the air TIMES 100%
The solubility of water in air is the
Maximum amount of water that a given volume of air can accommodate, & the solubility of water in air increases with increasing temperature
Relative humidity is also a
Function of temperature
If the sample is cooled to a temperature where the actual concentration of water exceeds the solubility of water in air,
Dew will form
(dew point temperature)
What another way to calculate relative humidity
Partial pressure of water/vapor pressure of water
What is it called when gaseous water molecules exert a pressure
Vapor pressure
At higher temperatures, more. water vaporizes into the air &
Exerts higher pressure
If the vapor pressure is higher at higher temperatures, then
The air has a greater capacity for water at that temperature
The maximum solubility of water in air is directly related to
The vapor pressure of water
Increasing humidity decreases
Partial pressure of oxygen available for breathing
What are the 4 components of the Kinetic Molecular Theory of Gases?
- gases consist of small particles whose volume is negligible compared to the volume of the gas
- Gas molecules are in constant, random motion
- The molecules in the sample show a range of kinetic energies, but the average KE depends only on the temperature
- There are no attractive or repulsive forces between the gas particles, so all collisions are elastic
In any sample of gas, the molecules are in
Constant random motion, but they do not move all at the same speed
What is the internal energy of a system?
The sum of the kinetic & potential energies of the molecules
If you increase the temperature of the sample, the added energy goes
Into increasing the average KE of the molecules
Temperature is directly proportional to the
Average KE
The distribution of kinetic energies among the molecules in a sample is given by
The Maxwell-Boltzmann speed of distribution
No molecule have
Zero KE
The number of molecules at a given KE increases to a maximum & then
Asymptotically approach zero again
A higher temperature means a
Higher average KE
Different gases have the same
Average KE if their temperature is the same
Boltzmann constant treats
Individual molecules
The ideal gas constant deals with
Moles of molecules
What is diffusion?
The movement of a substance from high to low concentration
What is Effusion?
The movement of a gas through a small opening
What is Graham’s Law of Effusion?
States the rate of effusion is inversely proportional to the square root of the molecular mass
The rate of effusion depends on the
Speed of the molecules
There are no attractive or repulsive forces between the gas particles so
All collisions are elastic
Which equation corrects the non-ideal behavior of real gases
The Van der Waals equation
What is Henry’s Law?
At a constant temperature, the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas at equilibrium above the gas-liquid interface
Increasing the partial pressure of a gas above a liquid will increase the
Amount of gas that dissolves in the liquid
In Graham’s Law, the rate of effusion of a gas is inversely proportional to the square root of
Its molecular weight
Diffusion of a fluid through a permeable membrane is dependent on what 5 five factors
- Concentration Gradient
- Tissue Area
- Fluid tissue solubility
4.Directly proportional to diffusion; membrane thickness & molecular weight are inversely proportional to diffusion
Diffusion is a
Passive process driven by entropy
A mole is the
Gram molecular weight of gas
The atomic (or molecular) weight is the
Additive weight of all the atomic particles, protons, neutrons & electrons in an atom or molecule
A mole of gas is equal to the
Molecular weight of the gas expressed in grams
The universal gas law is also called the
Ideal gas law
Pressure is purely the result of
Molecular collisions with the walls of a container
What is solubility?
The maximum amount of one substance (solute) that is able to dissolve into another (solvent)
What factors affect the solubility of solutes in solvents?
The intermolecular interactions between the substances, temperature & pressure
Gas solubility in liquids is inversely
Related to temperature; As temperature increases, less gas is able to dissolve into a liquid
Greater kinetic energy allows
Dissolved gas molecules to escape & prevents further dissolving
Gas solubility in a liquid is directly proportional to
Pressure (Henry’s Law)
What is Henry’s Law?
At a constant temperature, the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas at equilibrium above the gas-liquid interface
Increasing the partial pressure of a gas above a liquid will
Increase the amount of gas that dissolves in the liquid
What is Osmosis
The movement of water across a semipermeable membrane to equilibrate a concentration gradient
What is osmotic pressure?
The force needed to stop osmosis from occurring; exerted by plasma proteins & electrolytes in capillaries
What is Fick’s Law?
Diffusion of a gas across a semipermeable membrane is directly proportional to the partial pressure gradient, the membrane solubility of the gas, & the membrane area & is inversely related to the membrane thickness & molecular weight of the gas
Atmospheric gases are
Less concentrated at altitude & more concentrated at sea level
Atmospheric pressure is the
Gravitational force on gases in a given area
What is heat loss in decreasing order?
Radiation
Convection
Conduction
Evaporation
Which is the most significant mechanism of heat loss?
Radiation (from areas that receive the highest amount of blood flow)
What is convection?
Heat creates air currents (body transfer kinetic energy to air molecules on the surface of the skin-think currents)
What is conduction?
Transfer of heat via contact
What is evaporation?
Moisture evaporation from the patient’s skin as well as exhaled water vapor
What is vaporization
process of converting liquids or solids into vapors & requires energy
What happens when gas particles encounter container wall
Momentum is transferred to the wall
Solids are
Lattus
Force is
Change in momentum per unit time
Matter is composed of
Atoms & molecules that are in constant/chaotic movement
Volume is proportional to
The number of moles
As temperature of a substance increases, atoms & molecules
Vibrate with greater strength
When volume decreases, pressure
Increases
In Boyles Law is
Volume & pressure are inversely related; When volume decreases, pressure increases
What is Charles Law
Volume is directly proportional to Temperature
As temp increases, volume increases
What is Gay-Lussac’s Law?
Pressure directly related to temperature
What is Avogadro’s Law?
At equal temperature & pressure, equal volumes of gas contain an equal number of particles
Volume of gas is directly proportional to the number of gas molecules
A mole of any gas weighs
6.023 x 10 to the 23rd power
A mole of gas is equal to the
Molecular weight of the gas in grams
What is the memory device for gas laws?
P B V C T G
What is the constant in the ideal gas law?
8.314 Joules/Mole Kelvin
What is Dalton’s Law of partial pressure?
The partial pressure of a gas in a mixture is the pressure of a gas will exerts by itself under identical conditions of temperature & volume
total pressure of a gas is the sum of all the partial pressures of each of the component gases
What happens when your elevation increases?
The number of moles & partial pressure will decrease, while the percentage stays the same
What does Henry’s Law describe?
How the total of gas molecules dissolved in a liquid carries directly with the partial pressure of a gas overlying a liquid
As the temperature increases, what happens to the liquid & gas?
The liquid rejects the gas molecules, making them less soluble
What is Oswald coefficient?
Ratio used
Gas dissolved in a solvent (blood: tissue)
When a volatile liquid has low solubility,
It will equilibrate faster
rapid on/off
What is relative humidity?
Measure of saturation of water in the air
As temperature increases, air can hold more water
What is dew point?
Point at which the partial pressure of water & the solubility of the air are equal
Air can no longer hold anymore water & its current temperature & dew qill form
Partial pressure of water is equivalent to
The concentration of water & vapor pressure is equivalent to solubility of water of the air
Oxygen in the lungs
Is decreased due to the humidity provided as we breath in air
When gas is compressed, pressure will
Increase & volume is decreased
Causes temperature to rise= Adiabatic changes
With Adiabatic change, no energy is exchanged, only
Redistributed
Unequal heating causes weather
What is the Joule Thompson effect?
Gas compressed at high pressure & is suddenly released causing molecules to push away, decreasing temperature
Energy concentration effect
Think of a diesel engine
Pressure is the result of
Molecular collisions with the walls of the container
All molecules are moving but
Not at the same speed
The fraction of molecules is a function of
The mass, speed & temperature
Boltzmann constant provides
A measurement of the amount of energy corresponding to the random thermal motion of particles
Different gases will have the same
KE if temperature is the same
KE is directly proportional to the
Mass of an object & square of its velocity
Fick’s law of diffusion
Rate of diffusion across an area is greater where the concentration changes most rapidly
Diffusion is directly proportional to the concentration gradient
Diffusion is a passive process driven by
Entropy
What is directly proportional to diffusion
Concentration gradient
Tissue area
Fluid tissue solubility
What is indirectly proportional to diffusion
membrane thickness
Molecular weight
What is effusion
The movement of gas particles from one compartment to another through a small opening or porous membrane
Proportional to the square root of the molecular weight
Depends on the speed of molecules
larger molecule=slower speed
What is the Van Der Walls Equation
Corrects for the intermolecular attractions between the molecules & for the volume of the gas molecules
