Flashcards in Test3 Deck (108)
Characteristics of a Solid
1) Molecules arranged in a regular pattern
2) Molecules held firm in place but can vibrate within a limited area.
3) Molecules are touching
4) Molecules held in place by intermolecular forces
5) Not compressible
6) Have a definite volume and shape
Characteristics of a Liquid
1) Molecules are touching but flow easily around one another
2) Intermolecular forces are weak but are kept from flying apart by attractive forces
3) Have definite volume but no shape - liquids assume the shape of their containers
4) Not compressible
Characteristics of a Gas
1) Molecules fly in all directions at great speeds
2) Molecules are so far apart that the attractive forces btw them are insignificant
3) Have no volume or shape
4) Expand to fill a container
Name the following changes of states:
1) Liquid to gas
2) Gas to liquid
3) Gas to solid
4) Solid to gas
5) Solid to liquid
6) Liquid to solid
1) Liquid to gas - Vaporization
2) Gas to liquid - Condensation
3) Gas to solid - Deposition
4) Solid to gas - Sublimination
5) Solid to liquid - Melting
6) Liquid to solid - Freezing
What is heat of fusion
The amount of energy needed to melt solid into a liquid
What is heat of vaporization
The amount of energy needed vaporize a liquid into a gas
Difference btw heat and temperature
Heat is the amount of energy flowing into an object
Describe the process of melting
As heat energy is added to system, vibration btw particles become greater until that movement overcomes the intermolecular forces holding the molecules together, causing dissociation into a liquid state.
Describe the process of vaporization
A heat energy is added to system, the movement of the molecules continue to increase overwhelming the forces and particles begin to escape the liquid surface, vaporizing into a gas.
Characteristics of intermolecular forces
1) Determine how molecules interact with one another
2) Are electrostatic in nature
3) Are based on electron organization of the particles
4) Atoms tend to gain, lose or share electrons in order to achieve a total of 8 valence electrons (like noble gases)
5) The closer an element is to a noble gas, the more reactive is is (electronegative)
3 Types of intermolecular Forces
1) Dipole:Dipole (i.e. acetone) - polar molecule, boiling point 56C, liquid at room temp
2) Hydrogen (i.e. water) - Polar molecule, strongest type of dipole bond, boiling point 100C, liquid at room temp.
3) London Dispersion Forces (i.e. CH4) - Non-polar molecule, weakest type of intermolecular bond, boiling point -164C, gas at room temp
1) Describe chemical bonds using valence electrons
2) Lines = shared pair of electrons
3) Dots = lone pair of electrons
1) One atom donates an electron to another (i.e. Na+ and Cl- = NaCl)
2) Strongest type of bond
3) Usually a metal donating and electron to a non-metal
1) Atoms share electrons (i.e. H+ and O-- = H2O
2) Not as strong as ionic
Describe a Polar-Covalent Bond
When shared electrons spend more time around the more electronegative atom (i.e. H2O)
What is a Hydrogen Bond
1) When a H atom is bonded directly to O, N, or F.
2) H is left as a focused point of partial positive charge (i.e. H20 and NH3).
Describe Surface Tension
When molecule are attracted to each other on a surface . i.e. water molecules causes side-to-side and downward attraction forces, but no balancing attractions from above the liquid. The unbalanced force creates a "skin".
Describe surface tension in the lungs and how surfactant comes in to play
- Thin film of fluid lining the lungs (held together by surface tension) could cause the walls of the lungs to stick together and collapse
- Surfactant reduces the surface tension so this doesn't happen
Where is inhaled anesthetics absorbed in the lungs?
In the alveoli
Inhaled anesthetics come in what form? What form is it changed to, in order to be delivered to the PT??
- Come in Liquid form
- Changed into a vapor via vaporizers
Define Vapor Pressure
When molecules of a liquid escape into a gas phase, they collide with the walls of the container, exerting a force on the walls called vapor pressure
1) Volatility is the tendency of a liquid to change to a gas
2) Higher volatility = higher evaporation (I.E. ROH vs H20)
3) Higher volatility = higher vapor pressure
How does temperature affect vapor pressure
An increase in temp. causes an increase in vapor pressure
Simplify the Clausius-Capeyron equation
Ln(P) = (ΔHvap/R) * (I/T) + C
logP = A + B/T
The Clausius-Capeyron equation is used to calculate what?
The vapor pressure of a liquid
If Enflurane, A = 7.967 torr, B= -1687 torr*K
What is the vapor pressure of enflurane at 25C
- logP = 7.967 + (-1678/298K)
- logP = 2.34 (now take antilog to solve for P)
- On your calculator antilog = 10^x
- Antilog (2.34) - 10 ^2.34 = 217torr or 217 mmHg)
Find mole fraction of Enflurane if we run O2 through a vaporizer at 25C. The pressure of the mixture is 750 torr.
Xenflurane = vapor-of-enflurane/total-pressure
Xenflurane = 217/750 or 0.29
Define Boiling Point
Boiling point is the temperature at which the vapor pressure is equal to the ambient pressure (normally one atmosphere).
How does boiling point relate to the pressure of a liquid
- Boiling point of a liquid will increase if the pressure on the liquid is increased
- i.e. Water normally boils into steam at 100C, but in a sealed pressurized autoclave, the boiling point increases to 120C or more.