Test3 Flashcards
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
5) Compressible
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
Lewis Structure
1) Describe chemical bonds using valence electrons
2) Lines = shared pair of electrons
3) Dots = lone pair of electrons
Ionic Bond
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
Covalent bond
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
Describe Volatility
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
same as
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.
What is a phase Diagram
A diagram that shows the combined effects of temp. and pressure on the state of matter
What is the triple point of water
0.01C - temp at which water can exist in all 3 states (gas, liquid, solid)
Define a Solution
A homogenous mix of solutes in a solvent
Define Homogenous in regards to a mixture
When there are no visible phase boundaries i.e. salt water.
Define Miscible
Referes to liquids that mix evenly, forming a homogenous solution the do not separate i.e. water and acetone
Solution vs. Colloid vs. Suspension particle sizes
- Depends on particle size
1) Solution - particle size < 10^-7cm
2) Colloidal - particle size btw 10^-7 and 10^-5cm
3) Suspensions - particle size > 10^-5cm
Colloid vs. Suspension appearance and light effect
1) Colloid - transparent and no Tyndall effect
2) Suspension - cloudy and light dispersed in a ray
Types of Solutions
1) Liquid in liquid - i.e. 70% isopropanol and 30% water
2) Solid in liquid - i.e. 0.9% NaCl
3) Gas in liquid - i.e. CO2 in beer
4) Solid in Solid - stainless steel alloys
Define Colligative properties
Physical properties of a solution that are affected only by the concentration of solute particles, not the identity of the solute itself. i.e. by adding salt to water, you change the colligative properties of the water
Examples of Colligative Properties
1) Vapor Pressure
2) Boiling Point
3) Freezing Point
4) Osmotic Pressure
How does salt affect the freezing point and boiling point of water
1) Salt lowers freezing point of water
2) Salt raises boiling point of water
How does salt affect the osmotic pressure of blood
Salt raises osmotic pressure of blood
Define Molarity
Molarity (M) is moles of solute per liter of solution (give relationship of moles to volume)
mol/L (moles of solute/Liters of Solution)
Calculate the molarity of a D5W solution prepared by dissolving 1 g of glucose (C6H12O6) in enough water to give a total volume of 20 ml.
12C x 6 = 72
12H x 1 = 12
6O x 18 = 96»_space;> 72+12+96 = 180g/1mol.»_space;»>
180g/1mol = 1g/xmols»_space;» x = 5.56 x 10^-3 mols»_space;»>
5.56 x 10^-3 mols/.02L = .278M