CHem 111- Test 4- St. Thomas Flashcards
Atm–> torr–>psi
1.00 atm=760.0 torr= 14.7 psi
Ideal gas law
PV=nRT
what is R
0.08206 atm L/mol K
STP
298K and 1.00 atm
density (normal)
= Mass/volume
mass=
= moles x molar mass
density (special)
d= n x MM/nRT =P x MM/RT
kinetic energy, constant temp
massive objects have lower average velocity
kinetic energy (higher temperature)
objects have higher average velocity
larger or more polar (kinetic energy)
they are sticker molecules and deviate from normal behavior
another name for bonds
intrAmolecular forces,, hold atoms together
inter molecular forces
hold molecules together
3 types of intermolecular forces
london (dispersion) forces, dipole dipole forces, hydrogen bonding
london (dispersion) forces
- between nonpolar molecules
- increase in streath with greater mass
- form temporary dipole
- weaker for smaller molecules
dipole-dipole forces
- between polar molecules
- increase in strength with greater polarity
- form from permanent dipole
- intermediate strength
hydrogen bonding
- between polar molecules with H bonded to O, N or F
- More H-bonds make a stronger force
- Strongest IMF for molecultes of a smililar size
surface tension and viscosity
imcrease with increasing IMF strength
boiling point
the temperature where the vapor pressure = atmospheric pressure
Lower IMF means that…
- it is easier to separate molecules into gas phase
- there is a lower boiling point
- there is a higher vapor pressure
Change in Hvap
energy required to vaporize given amount of liquid into gas
total heat required equation
MCsΔT + ΔHfusn + MClΔT + ΔHvapn+M*CgΔT
M= mass, n = moles
boiling point is at what pressure
1 atm
crystalline
ordered, ionic and some covalent
amorphous
not ordered, mostly covalent
how are solids held together?
- Ionic solids
- Metallic solids
- Molecular solids
- network solids
ionic solid
held by ionic bonds
metallic solids
held by metallic bonds
molecular solid
held by IMFs- covalent molecultes (this is strong but weaker than covalent or ionic BONDS)
network solids
held by covalent bonds
melting point of a molecular solid is ____ than ionic or network
lower
properties of metal
malleable (bendable) and conduct electricity
what type of solid is diamon
network solid
why do solutions form?
when energy of solution < energy of solute and solvent
when energy of forces holding solvent + solute together < energy of forces holding together solute and solvent individually
IMFs (this time, 6 of them)
- london forces
- dipole dipole
- h bonding
- ion dipole
- ion induced dipole
- dipole induced dipole
ion dipole
strong force between an ion and a polar molecule
ion- induced dipole
force between ion and non-polar molecule
dipole-induced dipole
force between polar molecule and non-polar molecule
what does like dissolves like mean
solutes will mostly dissolve in solvents that have same IMF acting on them (also salts (ionic) dissolve in H2O)
electrolytes
solutions containing ions (conduct electricity)
stong electrolytes
completely breaks apart to form ions when dissolved- forms strongly conductive solutions (ionic compounds + strong acids)
weak electrolytes
partially breaks apart ti firn uibs wgeb dussikved- frs weakly conductive (weak acids + bases)
non-electrolytes
does not form ions when dissolved- non conducting solutions (soluable covalent compounds)
soluability of gases in water (temp)
higher temp= less gas dissolved
soluability of gases in water (pressure)
higher pressure= more gas dissolved
when are molecules stickier?
when they are larger or more polar
rate of diffusion
the square root thing
when will a gas behave most like an ideal gas?
at HIGH temp and LOW pressure
