Physic mini study guide 1 (states of matter-avogadros number) Flashcards
what is the boiling point?
the temperature at which a liquid’s vapor pressure equals atmospheric pressure.
what happens to the boiling point with increased atmospheric pressure?
increased boiling point
what happens to the boiling point with decreased atmospheric pressure?
decreased boiling point
describe where you may encounter decreased atmospheric pressure?
mountains
describe where you may encounter increased atmospheric pressure
HBO chamber
what is the specific heat mean?
the amount of heat required to increase the temperature of 1 gram of a substance by 1 degree celcius
what is the vapor pressure? describe?
the pressure that molecules in the gas phase exert on the walls of the container
what is the vapor pressure primarily dependent on?
the liquid’s temperature
with the temperature of a liquid increases what happens to the vapor pressure?
increases
with the temperature of a liquid decreases what happens to the vapor pressure?
decreases
what is the vapor pressure at body temperature?
47 mmHg
what does not affect vapor pressure?
altitude
what is the process called, by which a liquid is converted to a gas?
vaporization
vaporization requires what?
energy (heat)
describe what latent heat of vaporization?
the number of calories required to convert 1 gram of liquid to vapor without a temperature change
what is the vapor pressure of sevoflurane?
157 torr
what is the vapor pressure of isoflurane?
238 torr
what is the vapor pressure of halothane?
243 torr
what is the vapor pressure of desflurane?
669 torr
why does desflurane require a special vaporizer?
because its vapor pressure is so close to atmospheric pressure that it becomes chaotic that it all wants to go to a gas resulting in inconsistence.
if sevoflurane is placed in isoflurane’s vaporizer, what could happen? how?
you could overdose your patient
because the isoflurane has a higher vapor pressure than sevoflurane
fresh gas flows over the anesthetic liquid carrying some of the agent present in the gas phase to the patient for anesthetic purposes, however, this will cool the liquid which reduces what?
the vapor pressure of the liquid and thus the vaporizer output
how does modern vaporizers compensate for the temperature changes due to the fresh gas flow cooling effect? 3 examples?
1) they use metals with high thermal conductivity. they transfer heat easily like cooper and bronze
(2) they use a temperature compensation valve to modulate the amount of FGF that is directed into the vaporizing chamber(SEVO, ISO)
(3) they apply direct heat to the anesthetic liquid (DES)
describe the joule thompson effect?
a gas stored at high pressure that is suddenly released from its container quickly looses it speed and temperature (due to a loss of kinetic energy)
Rapid compression of a gas intensifies its kinetic energy, causing the temperature to rise
remember JOULE is COOL
what is the adiabatic process?
a process that occurs without gain or loss of energy (heat)
give an example of an adiabatic process?
rapid expansion or compression of a gas where there is no transfer of energy.
describe what the critical temperature is?
the highest temperature a gas can exist as a liquid
what is the critical temperature of nitrous oxide?
36.5C
what is room temperature in celcius?
20C
what is the critical temperature of oxygen?
-119C
what is the critical temperature of carbon dioxide?
31 C
what is the critical temperature of air?
-140 C
what is the critical temperature of nitrogen?
-147 C
describe what critical pressure is?
the minimum pressure required to convert a gas to a liquid at its temperature
what is the absolute temperature scale measured in?
kelvin
0 degrees celcius equals what in kelvin?
273 Kelvin
what is the equation to convert kelvin to celsius
K - 273
what is the equation to convert celsius to kelvin
C+273
There is ______ degrees between the boiling and freezing points of water on the Fahrenheit scale
180
There is _______ degrees between the boiling and freezing points of water of the celsius scale?
100
what is the equation to convert fahrenheit to celsius
(F-32) x 5/9
what is the equation to convert celsius to fahrenheit?
(Cx1.8) +32
air pressure results from ____ pulling on the atmosphere.
gravity
atmospheric pressure, is the pressure associated with ____ in the atmosphere?
gas
what is used to measure pressure on gas cylinders?
bourdon gauge
how does a bourdon gauge measure gas cylinder pressure?
measures the pressure difference between the pressure exerted by the gas in a cylinder and the atmospheric pressure.
what is gauge pressure?
the pressure of a system above or below atmospheric pressure
what is the absolute pressure?
a total of atmospheric pressure plus the gauge pressure
1 atm equals how many mmHg
760
1 atm equals how many torr?
760
760 torr equal how many bar
1
1 bar equals how many kPa
100 kPa
100 kPa equals how many cm H2O?
1033
1033 cm H2O equals how many lb/inch2?
14.7 lb/inch2
1 mmHg equals how many cm H20?
1.36 cm H2O
1 cm H2O equals how many mmHg?
0.74 mmHg
what is the equation for pressure?
force/area
increased area = _____ pressure
decreased
decreased area = ____ pressure
increased
what is the standard molar volume?
22.4 L
what is STP?
standard temperature and pressure, used to compare sets of data between gases
0 celsius = ____ atm
1
273.16 K = _____ mmHg
760 mmHg
______ kPa = 273.16 kelvin
101.325 kPa
_____ kelvin= 760 torr
273.16 Kelvin
Avogadro’s number is what?
1 mole of any gas is made up of 6.023 x 10^23 atoms
A mole of a gas is equal to the __________ of that gas in grams
molecular weight
meaning if the molecular weight of helium is 4 grams, then 4 grams of helium contains 6.023 x 10 ^23 atoms
diatomic gases have ____ molecules?
2
give an example of a diatomic molecule?
oxygen
so one mole of oxygen weighs?
32 grams instead of 16 grams, because it is diatomic
so how many atoms is in 32 grams of oxygen?
6.023 x 10^23 atoms