unit 3 quiz Flashcards
london dispersion
for all molecules
dipole dipole
polar molecules
asymmetrical molecules w/ only nonmetals
includes hydrogen bonding
hydrogen bonding
strong type of dipole dipole
hydrogen itself has to bond with either F O N
strong but difficult to compare IMF
ionic and metallic
ionic
metals w nonmetal
metallic
only metals
covalent network
strongest IMF
dipole induced dipole
one substance polar and the other is non polar
the IMF increases w magnitude of dipole of polar molecule and with polarizabiity of nonpolar molecule
ion induced dipole
nonpolar substance w ion
strength increases w larger charged ions(smaller radius) and more polarizable molecules
ion dipole
polar substance w ion
stronger than dipole dipole
strength increases w large charged ions(smaller size) and more polar molecules
what properties increase with IMF
boiling/melting/freezing pt enthalpy of fusion/vaporization viscosity surface tension lattice energy
what properties decrease with IMF
vapor pressure
solubility(depends on polarity of solvent and solute)
what are the 4 basic types of solids
ionic solids
covalent networks of solids
molecular solids
metallic solids
due to strong interactions between ions
ionic solids have high vapor pressure high melting pts and high boiling pts
electrostatic attraction
attraction between positive and negative ions
why are ionic solids brittle
due to repulsion of like charges when one layer of solids slides across the other layer
when do ionic solids conduct electricity
(when charged which is a given)
web ions are mobile
when ionic solid is melted
or dissolved in water or another solvent
covalent networks have atoms at their lattice pts with
strong directional covalent bonds
covalent solids are only formed of
nonmetal
how are covalent solids characterized
hardness
strength
high melting point
molecular solids are composed of
distinct individual units of covalent lay honded molecules attracted to each other through weak IMF
do molecular solids conduct electricity
why or why not
no becuase their valence e- are tightly held w/in the covalent bonds and line pairs of each constituent molecule
metal alloys conduct with what
sea of electrons
metallic solids are packed together and bonded to each other
equally in all directions
ionic properties
poor conductors of heat and electricity high melting pt hard but brittle relatively dense dull surface
molecular properties
poor conductors of heat and electricity low melting pt soft low density dull surface
covalent network peoperties
poor condusctors of heat and electricity high melting point very hard and brittle low density dull surface
metallic properties
good conductors of heat and electricity melting points depend on e-config ductile and malleable high density usually lustrous
When deciding which compound will have a lower boiling point consider
First consider IMF then if the same consider Number of electrons, polarizability
Increasing IMF forces by structure diagrams
Consider surface area, more branches is less polarizable
Drawing sand mixed with water
Sand on bottom, water on top
Sand particles close together, water particles further apart
Consider particle size, atomic radius, also
Why do gas particles follow the ideal gas law
They don’t have IMF
Low pressure vs high pressure particles
Low pressure: particles far part
High: particles close together
Partial pressure formula
Add up the moles of the mixture of
each element of gas
Divide each element by the total
Multiply by the total pressure stated in the problem
total pressure formula
PV=nRT
What is the n in PV=nRT
Moles
What is the R in PV=nRT
0.0821
Kinetic molecular theory
The size of a gas particle is so small domeñare w/ distance between particles that volume is ignored
Gas particles are in constant random motions, bumping off walls
Gas particles have no attractive or repulsive force
Draw a 1L vessel containing 2 moles of H2 at 200K
Since it’s about 2 moles, consider a number easily multiplied by 2 like 3
Remember more heat means faster movement which means more pressure
How to find higher average molecular speeds
Consider grams or mass of elements
The lighter the weight, the faster it moves
if your doing stoic and you have O2 how would you write the fraction
32g O/ 1 mol O2
Or
1 mol O2/32g O
When are gases more ideal
When pressure is low and temp is high
Boyles law
As gas pressure increases, volume decreases
P1V1 = P2V2
Charles law
As the temperature decreases, the volume decreases
V1/T1 = V2/T2
Avogadros law
As the number of moles of gas increase, the volume increases
V1/N2 = V2/N2
What forces increase with IMF strength(3)
Melting point, surface tension, heat of vaporization
What forces decrease with IMF (2)
vapor pressure, volatility(cause of evaporating)
avogadro’s number
6.02*10^23
how many torr in 1 atm
760 torr
carbon di sulfide formula
CS2
fluorometham formula
CH3F
ammonia vs ammonium
NH3 vs NH4
