Lecture 4_190612 Flashcards
States of Matter
1) Solid
2) Liquid
3) Gas
Melting
Solid → liquid = melting
Freezing
Liquid → solid = freezing
Boiling
Liquid → gas = boiling (evaporation or vaporization)
Condencing
Gas → liquid = condencing (condensation)
Sublimation
Solid → gas = sublimation
Deposition
Gas → solid = deposition
Ionic Bonds
Bonds between metals and non-metals, and involve the EXCHANGE of electrons.
Covalent Bonds
Bonds between non-metals and non-metals, and involve the SHARING of electrons.
NOT broken randomly, but by enzymes.
Polar Covalent Bonds
Covlent nonds where the atom with the higher electronegativity will get the shared electron more, while the atom with the lower electronegativity will get the electron less,
partial “-“ on the high electronegativity atom
partial “+” charge on the low electronegativity atom
resulting in dipoles!
Intermolecular Forces
forces are the forces between molecules
*stronger the forces = less volatile the matter (higher melting and boiling points)
From strongest to weakest:
•force between permanent dipole and ion
•force between permanent dipoles
- Hydrogen bonding = special case (much stronger)
- H -> H, C, N, O
•force between permanent dipole and induced dipole
•force between induced dipoles (London force)
Induced dipole
= London forces = van der Waals forces = temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form TEMPORARY dipoles ~ “passer-by atoms”
Solute
“being desolved”
Solvent
“desolving”
Solubility
“Like dissolves like.”
Polar solvents dissolve polar solutes
Non-polar solvents dissolve non-polar solutes
Hydrophilic Interactions
high water-soluble molecules, polar molecules
substrate binds to water
polar (charged) molecule is attracted to the charges within the water molecule.
Hydrophobic Interactions
low water-soluble molecules, nonpolar molecules
*usually have a long chain of carbons that do not interact with water molecules
EX: mixing of fat and water
Ampipathic
both hydrophilic & hydrophobic interactions
*philic on one end or phobic on the other
Electronegativity
O > N > C > H
OH- > CN-
TABLE 2-3
STUDY!!!
SLIDE 11
SUDY!!!
Surface Tension
If a liquid has a high attractive force with itself, and a low attractive force with a surface (cohesion), it will exhibit high “surface tension”.
Capillary Action
Cohesion creates surface tension
Adhesion attracts the liquid to the wall of container
LaPlace’s Law & Blood Vessels
T = P x R, stress = T/h T = tension, P = pressure, R = lumen radius, h = wall thickness
increase R = increase T = stress
increase h = decresed stress
LaPlace’s Law & Alveoli
ΔP = Pinside - Poutside = T (2/R) – for a sphere
T = 0.073 N/m – surface tension for pure H2O
T ≈ 0.02 N/m – with surfactant
1 kPa ≈ 10.2 cm H2O
Opening pressure needed for collapsed alveoli in ARDS:
P ≈ 50 cm H20
For normal alveoli:
P = 4 cm H2O
*”+” pressure destroys already open alveoli
Boiling Point
liquid boils when its vapor pressure is equal to the pressure it is exposed to
For example, in the graph, at 100 ºC the vapor pressure of water is 760 mmHg (1atm)
Heat of fusion
energy required to melt a mole of a material
Q = ΔH-fus * m
*while melting delta temp = 0
Heat of vaporization
energy required to boil a mole of a material
Q = ΔH-vap * m
*while boiling delta temp = 0
Specific heat of water
= 1 cal/g/ºC = 4.18 J/g/ºC
Specific Heat (Cp)
The amount of energy required to heat an object is:
Q = Cp * m * ΔT
Energy Changes and Changes of State
A) ice absorbs heat and warms up to 0 degC
B) ice melts, requires “heat of fusion” ~delta temp = 0
C) water absorbs heat and warms up to 100 degC
D) water boils, requires “heat of vaporization” ~delta temp = 0
E) steam (water vapor) absorbs heat
Phase Diagrams
STUDY slide 20!!!
