phases gases and solutions Flashcards
basic phases of matter
solid liquids and gases
what forces determine which phase a substance will be in?
intermolecular forcers
solid
phase with rigid and tighly packed atoms
- fixed volume and noncompressible
- crystalline or amorphous
lattice energy
amount of energy required to disrput the crystalline structure of a salt into cations and anions
amorphous solids
solids without a crystalline structure (glass and silcone)
liquid
phase with fixed volume and are not compressible but do not have a fixed shape
viscocity
property of liquids: resistance to flow
gas
phase with no fixed volume or shape
- compressible
compressibility
lack of fixed volume (only a property of gases)
phase change
when substance transitions from one phase to another
melting/fusion
solid to liquid
freezing
liquid to solid
evaporation/boiling
liquid to gas
condensation
gas to liquid
sublimation
solid to gas
deposition
gas to solid
endothermic phase changes
melting, evaporating, sublimation
require heat input
breaking bonds
exothermic reactions
freezing, condensation, deposition
release heat
forming bonds
is bond formation exothermic or endothermic
exothermic
heat of fusion
point in phase change where the added heat is no longer increasing the temperature and is focused on breaking the intermolecular forces
heat of vaporization
heat required to convert liquid to gas where temperature is no longer rising and heat is focused on breaking intermolecular forces of liquid
specific heat capacity
amount of heat required to raise the temperature of one unit mass of a substance by 1 degree
specific heat equation
Q = mc ∆T
q is heat, m is mass, c is specific heat capacity
heat at phase changes
typically a ratio because temperature remains constant
heat between phase changes
q= mc ∆T
how can a gas be converted into solid
increase in pressure or decrease in temperature
what phase changes are promoted by a decrease in pressure and an increase in temperature
solid to liquid
liquid to gas
solid to gas
triple point
point at which solids liquid and gases are at equillibrium
critical point
end of the liquid-gas interface
- above this point the substance exsist as a supercritical liquid
high tempertaure and low pressure promotes which phase
gas
low temp and high pressure favors which phase
solid
vapor pressure
gas is in equillibrium with liquid
gas @ STP
volume 22.4L
ideal gas
- average KE of gas molecules is proportional to temperature
- gas particle has no volume
- gas particles do not exert attractive forces on one another , although they do exert forces on the container they are in –> all collisions are elastic
when do gases deviate from ideal gas law?
at high pressure and low temperature
when do gases behave most ideal?
low pressures and high temperatures
boyle’s law
pressure and volume of a gas are inversely proportional at constant temperature
V1P1=V2P2
what happens to the pressure of a gas if the volume increases
pressure decreases
charles law
volume and temperature of a gas are directly proportional under constant pressure
V1/T1 = V2/T2
what happens to the volume of a gas if the temperature is increased at constant pressure
volume with increase with temperature
ideal gas law
PV=nRT
n is number of moles of gas
R is gas constant
mole fraction
Ngas/Ntotal
partial pressure
pgas/Ptotal
Dalton’s Law
Pgas = Xgas*Ptotal
partial pressure of gas = total p * moles of gas
solution
homogenous mixture
dissolutions
solutes dissolved in solvent
supersaturated
excess solute not dissolved
crystallization
supersaturated solute creates nucleation site for solute to parcipitate out and form a cyrstal
molarity
mols solute/ L solution
molality
moles of solute/ Kg solvent
normality (N)
number of equivilent reactive species per liter of solution
N= equivelent solute/ L solution
normality for acids
N = molarity * (# of H+ in acid)
colligative properties
vapor pressure reduction
boiling point elevation
freezing pt reduction
osmotic pressure
Raoult’s Law
P=XaPa
p is vaport pressure of solution
Pa is vapor pressure of pure solvent
Xa is mole fraction of solvent
boiling point elevation
∆T= iKb*m
- t is change in boiling point elevation
- i is ionization factor
- kb is boiling point constant
- m is molal solute conc
reducing vapor pressure does what to boiling point
increases
what does added solute do to the freezing point
decreases
freezing point depression eqn
∆Tf= iKf*m
osmotic pressure
Π= iMRT
pressure required to prevent osmosis
M= n solute/ L solution
solubility
equillibrium process between nondissolved and dissolved forms of substance
equillibrium constant (Ksp)
solubility product constant [p][p]
high ksp
substance readily dissolves into solution
low ksp
largely insoluble
common ion effect
decrease in solubility of an ionic compound by adding a solute compound with an ion in the precipitate
are alkali metals soluble
yes
are nitrates soluble
yes
are chlorates soluble
yes
are halides soluble
yes
is AgCl soluble
no
is PbAg soluble
no
is HgI soluble
no
are carbonates (CO3 2-) soluble
no
PO4 2- soluble?
no
OH- compounds soluble?
no
is caoh2 soluble?
soluble
is baoh soluble
yes, exception to rule
