ch. 10 and 11 Flashcards
how to tell if a molecule is polar
positive and negative end
if a structure is linear
the two polar bonds cancel out making it a nonpolar molecule
sp3 hydridization means
bent electron geometry, polar and doesnt cancel out
intermolecular forces for a pure substance are
covalent and based on positive and negative charges attract- not a chemical bond
dipole- dipole
polar molecules- about 1% as strong as a covalent bond
hydrogen bonding
same as dipole but stronger. not a covalent bond but an intermolecular force
requirement for hydrogen bonds
covalent bond between H, N,O or F
unusually high boiling point for
H2O, HF, NH3- large intermolecular forces
London dispersion forces
electrons slosh around- can induce temporary dipoles- nonpolar molecules, weak attraction forces
do all molecules have london forces
yes- more electrons, more I.M forces
polarizability
I.M forces increase with molar mass (# of electrons)
super critical fluids
density of a liquid but fill container like a gas- acts as a solvent
critical temp
temp above which the vapor cannot be compressed to a liquid
what is the molality definition
moles SOLUTE/ kg SOLVENT
molarity definition
moles SOLUTE/ L SOLUTION
for solutions as the concentration of the solute goes up
the boiling point, and osmotic pressure go up, but the freezing point and vapor pressure go down
colligative properties
dependent on concentration of solute- independent of the chemical properties of solute, depend on nature of solvent
what is i
vant hoff factor- # of particles per solute- moles PARTICLES/ moles SOLUTE
enthalpy of vaporization
change for liquid going to gas - Hvap
enthalpy of fusion
change in H for solid going to liquid- Hfusion
viscosity
how “thick” a liquid is- H2O has a high viscosity but not compared to honey. -resistance of a liquid to flow
surface tension
why bugs can walk on water. resistance of a liquid to increases in surface area. droplets- attracted to itself.
what temperature does water boil at
100 degrees F but 373 K
H vap for water in the equation for 2 data points
40,670
what must we recognize when trying to figure out the vant hoff factor
polyatomic ions- only count as 1
for exo and endothermic what are the characteristics
endothermic is positive and exothermic is negative - H solution can be large or small, + or -
polar solutes dissolve in
polar solvents
between polar and nonpolar which one is water loving
polar molecules are hydrophillic and nonpolar is hydrophobic
what is henrys law and its characteristics
c=K*P c=conc. of gas P=partial pressure. concentration of gas is directly proportional to the partial pressure of the gas
miscible mean
100% soluble in water
how to rank solubility in water
the longer the chain of carbon the more hydrophobic is it because of the nonpolar bonds
if ionic it is always going to be more soluble in
water- universal solvent
water solubility depends on
if there are hydrogen bonds, polar
as conc. of a solute goes up
boiling point goes up
freezing point goes down
vapor pressure decreases
osmotic pressure increases
