states of matter Flashcards
what holds molecules rigidly in place in solids
intermolecular forces
liquids volume and shape
definite volume, no definite shape
molecules in liquids
very close together, but can flow past each other
intermolecular forces on liquids
strong enough to hold molecules in a condensed phase. not strong enough to prevent molecules from sliding past each other
gases shape/volume
no definite shape/volume
intermolecular forces in gases
essentially zero between gases and molecules
ionic bonds
results from coulombic attraction between oppositely charged ions
ionic compounds are almost always
solids
covalent bonds result from
sharing one or more pairs of electrons
octet rule
states that atoms want to be a noble gas. or at least have a noble gas configuration - species with the same electron configuration are termed isoelectric - this is achieved by giving each atom access to 8 electrons
species with the same electron configurations are termed
isoelectric
??octet rule is achieved by giving each atom access to
8 electrons
kinetic molecular theory of matter
attempts to describe all the states of matter and the conversion between them
valence bond theory
a covalent bond results from the overlap of two electron clouds. this allows the electron on 1 atom to spend time around atom 2’s nucleus and vice versa
VSEPR theory
valence shell electron pair theory. atoms are bound into molecules by electrons. electrons repel each other. therefore the groups bonded to a central atom try to get as far apart from each other as possible. the goal is to minimize electron pair repulsion around a given central atom
electronegativity
the tendency of an atom in a molecule to attract shared electrons to itself.
what is most electronegative element
fluorine - the closer an atom is to fluorine, the more electronegative it is
intermolecular forces
attractive forces between molecules or atoms or ions
London forces are created by
instantaneous dipoles
london forces get stronger with
larger atoms/ molecules
london forces are much weaker than
dipole-dipole or H-bonding
hydrogen bonding strength
generally stronger than dipolar attractins
hydrogen bonding is
the attraction between a hydrogen bonded directly to an O, N, or F and another electronegative atom
ion dipole attraction
the attraction between an ionic charge and a polar molecule
ion dipole attraction allows
ionic solids to dissolve in water
hydrogen bodies in a negative way cause
atelectasis
like desolves
like
more intermolecular forces does what to boiling and melting points
higher
substances with greater intermolecular attraction have greater
surface tensions
a molecule near the surface of a droplet will experience
net inward force
surface tension will allow an object having a greater density than a liquid to
float in the liquid
LaPlace’s law
when the liquid is in contact with another surface, this curling creates a pressure difference which is described by La Place’s law.
LaPlace’s law can be used to explain
why the surface tension on a blood vessel wall will depend on the radius of the vessel.
the tension on the surface of the blood vessel is ____ proportional to the radius of the vessel
directly
wall tension is proportionate to
radius (laPlace’s law)
as the radius increases, wall tension
increases
soap makeup
polar (hydrophilic) head and non-polar (hydrophobic, greasy) tail
monolayers
the greasy tails stick out of the surface of water, which breaks down the surface tension of water
micelles
tails can dissolve in each other forming a sphere. this creates a non-polar microenvironment in the water
vapor pressures
the most energetic molecules in a liquid have sufficient kinetic energy to escape from the surface of a liquid into the gas phase, and once the molecules are free as gases, they exert a pressure.
as temp increases, vapor pressures
increase. calusius-clapeyron equation
the process of evaportion in a closed container will proceed until
there are as many molecules returning to the liquid as there are escaping. (saturated vapor pressure)
the temp at which the vapor pressure is equal to the atmospheric pressure is
boiling point
dynamic equilibrium
when there is a balance between vaporization and condensation
aneurysm application to laplace?
they are approximately spherical, so the tension on the wall of the aneurysm rises as the radius is divided by two. so, while not a good diagnosis, they represent a physical means for lowering the tension on a blood vessel
capillary being smaller will withstand pressure better than
larger artery or vein
volatility
the tendency of liquid to evaporate
volatility
the tendency of liquid to evaporate
solid to liquid
melting
liquid to solid
freezing
liquid to gas
vaporization
gas to liquid
condensation
solid to gas
sublimation
gas to solid
deposition
what does temp do to vapor pressure
increases
vaporization is an _____ process
endothermic
the unit of energy for vaporization (Hvap) represents
the energy needed to break intermolecular forces and allow molecules to escape into the gas phase
fusion
endothermic - solid to liquid
760
atmospheric pressure
phase diagrams show
combined effects of temp and pressure on the state of matter
which gas has the highest vapor pressure
desflurane 669
vapor pressure of isoflurane
239
vapor pressure of sevoflurane
157
triple point of phase diagram of water
the single temp and pressure combination where all three phases an exist in equilibrium with each other
critical point
when temp and pressure exceed critical point, system becomes a supercritical fluid… have the flow properties of gases but densities similar to liquids and no surface tension
as diameter of a tube decreases, speed
increases
if an object sinks, boyount force is
smaller
if an object floats, boyount force is
larger
as the speed of a fluid increases, the pressure exerted by the fluid
decreases (bernoulli effect)
bernoulli effect
as the speed of a fluid increases, the pressure exerted by the fluid decreases
venturi flowmeter is explained by
bernoulli effect
