Chem/Phys Exam III Flashcards
4 physical states of matter
Solid, liquid, gas, plasma
Solids
-have a definite shape and volume
-have a movement (vibrate)
—molecules are touching and do not separate
-held in place by intermolecular forces
-non-compressible
Liquid
- Definite volume, no definite shape
- molecule are touching but have more movement
- intermolecular forces are weaker and allow the molecules to slide past each other
- non-compressible
Gases
- have no definite shape or volume
- expand to fill the container
- molecules are not touching and have more movement
- no intermolecular forces
- Compressible
Heat of Fusion
Amt. of E necessary to melt a solid int liquid phase
Heat of Vaporization
Ant. of E necessary to vaporize a liquid into gas phase
3 types of intermole-cular forces
London dispersion, dipole-dipole, hydrogen bonding
Dipole -dipole forces
-polar molecule
Ex: acetone
-boiling point 56C, liquid @room temp
Hydrogen bonding
- polar molecular
- Strongest type of dipole bond
- boiling point 100C, liquid @room temp
London dispersion forces
- non-polar molecule
- ex. CH4
- weakest type of inter-molecular bond
- boiling pt. -164, gas @room temp
Type of Bond
Ionic and Covalent
Ionic Bond
- one atom donates electron to another
- ex: Na+ and CL-= NaCL
Covalent bond
-atoms share electrons
Ex. H+ and O- = H2O
Hydrogen Bonding occurs when:
- a H atom is bonded directly to O, N or F
Surfactant Lowers
Surface tension
Without Surfactant
- the thin film of fluid lining the alveoli could cause the walls to stick together and collapse
- surfactant reduces the surface tension so this doesn’t happen
Inhaled anesthetics comes in what form?
Liquid
How do inhaled Anesthetics change from liquid to vapor
Vaporizers
Vapor pressure
-when molecules of a liquid escapes into the gas phase, they collide with the walls of the container, exerting a force on the walls
An increased in temp causes an increase in
-vapor Pressure and in “Volatility”
For enflurane, A= 7.967
Torr, B= -1678 torr x K
What is the vapor presser of enflurane at 25C?
LogP=7.967+-1678/298K
LogP=2.34(now need to take the antilog to solve for P)
On your calculator, antilog is 10x
Antilog (2.34)= 102.34= 217 torr (same as 217mmHg)
What does Vapor Pressure determine of a volatile anesthetic in a gas mixture
-mole fraction or Partial Pressure
Ex: If O2 is sent through a vaporizer with liquid enflurane, the composition of the O2 enflurane mixture will depend on the temp. Of the vaporizer and the pressure of the O2.
The mole fraction is calculated as follows:
Xenflurane= vapor pressure of enflurane =217torr
Total pressure 750= 0.29
Find Mole fraction of enflurane: We run O2 at 750 torr through a vaporizer so that it becomes saturated with enflurane. In this case, we are at room temp. 25C; the partial pressure of enflurane.
The pressure of the mixture is still 750 torr, but part of this is now composed of enflurane
Boiling point
The temp at which the vapor pressure is equal to the ambient pressure (normally one atmosphere)
Boiling point of a liquid will increase if:
The pressure on the liquid is increased
Ex: Water normally boils into steam at 100C, but in a sealed pressured auto-clave, the boiling point increase to 120C or more.
Gas to solid phase change
Deposition
Solid to Gas phase change
Sublimation
Heat of fusion
Energy required to melt a solid into liquid
Heat of vaporization
Energy required to vaporize a liquid into gas
Intermolecular forces
Dipole-dipole: partial charge on molecules interact.
Hydrogen bonding: strongest type of dipole bond.
London dispersion forces: non-polar molecules, weakest intermolecular bond due to transient shifts in charge locations on molecular.
Example of dipole-dipole bond
Acetone -boils at 56C, liquid at room temp
London dispersion force example
CH4 (methane) boiling pt: -164C, gas at room temp
Covalent vs. ionic bonds
…
Surfactant
Reduces surface tension, and amphipathic molecules line up with hydrophilic end to alveoli wall white hydrophobic end faces in
High volatility meaning
Liquid has a higher evaporation, or tendency to change into a gas
Vapor pressure in relationships to atmospheric pressure (760torr)
when vapor pressure of a liquid reaches ambient pressure (760torr), this is its boiling point
Clausius- Clapeyron equation (know for test)
Modified form that we need to use:
LogP= A+ B/T
P= vapor pressure A= will always be given (torr) B= will always be given (torr * K) T= degree in K
A and B are set values for each specific liquid
