UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
1. Intermolecular forces and how they affect physi- *dipole-dipole*: polar co-
cal properties /purification techniques: dipole-dipole, valent molecules such as
electrostatic, hydrogen, ion, london, aldehydes and ketones.
positive and negative end.
polar molecules must be
close together for force
to be significant. weak-
er than ion-dipole forces;
increase with polarity of
molecule.
*electrostatic*: occur be-
tween charged species,
cations and anions, and
are responsible for very
high MP and BP of ionic
compounds and metals
*hydrogen bonding*: hy-
drogen atom in a polar
bond (NOF). considered a
dipole-dipole interaction.
quite polar.
*ion-dipole*: interaction
betwween a charged ion
and apolar molecule.
cations are attracted to
negative end of dipole,
and anions are attracted
to positive end.
*london dispersion*: de-
pendent on surface area
and polarizability of the
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
surface of the mole-
cule. only types of forces
NON-polar covalent mole-
cules can experience. re-
sult from the movement of
electrons in the molecule,
which generates tempo-
rary positive and negative
regions in the molecule.
2. melting point and melting point range solid has ordered crys-
tal lattice structure. heat
makes this structure move
enough to the point where
it becomes a liquid. The
melting point is how
much energy it takes to
make this lattice structre
move. Impurities disrupt
the crystal lattice, so im-
purities make a structure
easier to melt. MP also
broadens when a com-
pound is impure. If there
is water in the solid, it is
impure. solid will stick to
side of capillary if still wet.
Best way to determine MP
range if you dont know the
MP range:
take a quick measurement
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
to get a rough estimate,
then take a second, more
careful measurement.
3. limiting reagents and percent yields *limiting reagents*: the
compound that runs
out first. when limiting
reagent runs out, reac-
tion can no longer pro-
ceed and other com-
pound is considered in
excess. tell which is lim-
iting reagent by convert-
ing grams or mg used to
moles using molar mass.
when you have moles, use
the stoichimetric ratios to
see which is the smaller
amount of moles (mole of
reagent under mole pro-
duced of product); this
is your limiting reagent.
could also compare mole
ratios between reagents
to see how much you
would need of the other
reagent to make reaction
go to completion. use lim-
iting reagent to see how
much product we will get.
*percent yield*: actual
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
yield/theoretical yield X
100. If you expect 10 g
but only get 8.4, your %
yield is 84%. get theoret-
ical yield by taking lim-
iting reagent and seeing
how much product can be
made by LR. convert g to
mol of LR, then convert
mol of LR to mol of prod-
uct; use molar ratio for
this. then convert the mol
of product by multiplying
molar mass of product.
4. distillation: ideal liquids/Raoults law *ideal liquid*: a liquid that
in incompressible (densi-
ty is constant), irrotation-
al (no turbulence, flow is
smooth), and nonviscous
(fulid has no internal fric-
tion). they do not exist in
nature. Does not change
composition by mixing. it
obeys Raoult's law for all
compisitions.
*Rauoults Law*: shown in
picture. total pressure can
be found by adding up
partial pressure; partial
pressure can be found
Study online at https://quizlet.com/_j58lf1
1. Intermolecular forces and how they affect physi- *dipole-dipole*: polar co-
cal properties /purification techniques: dipole-dipole, valent molecules such as
electrostatic, hydrogen, ion, london, aldehydes and ketones.
positive and negative end.
polar molecules must be
close together for force
to be significant. weak-
er than ion-dipole forces;
increase with polarity of
molecule.
*electrostatic*: occur be-
tween charged species,
cations and anions, and
are responsible for very
high MP and BP of ionic
compounds and metals
*hydrogen bonding*: hy-
drogen atom in a polar
bond (NOF). considered a
dipole-dipole interaction.
quite polar.
*ion-dipole*: interaction
betwween a charged ion
and apolar molecule.
cations are attracted to
negative end of dipole,
and anions are attracted
to positive end.
*london dispersion*: de-
pendent on surface area
and polarizability of the
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
surface of the mole-
cule. only types of forces
NON-polar covalent mole-
cules can experience. re-
sult from the movement of
electrons in the molecule,
which generates tempo-
rary positive and negative
regions in the molecule.
2. melting point and melting point range solid has ordered crys-
tal lattice structure. heat
makes this structure move
enough to the point where
it becomes a liquid. The
melting point is how
much energy it takes to
make this lattice structre
move. Impurities disrupt
the crystal lattice, so im-
purities make a structure
easier to melt. MP also
broadens when a com-
pound is impure. If there
is water in the solid, it is
impure. solid will stick to
side of capillary if still wet.
Best way to determine MP
range if you dont know the
MP range:
take a quick measurement
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
to get a rough estimate,
then take a second, more
careful measurement.
3. limiting reagents and percent yields *limiting reagents*: the
compound that runs
out first. when limiting
reagent runs out, reac-
tion can no longer pro-
ceed and other com-
pound is considered in
excess. tell which is lim-
iting reagent by convert-
ing grams or mg used to
moles using molar mass.
when you have moles, use
the stoichimetric ratios to
see which is the smaller
amount of moles (mole of
reagent under mole pro-
duced of product); this
is your limiting reagent.
could also compare mole
ratios between reagents
to see how much you
would need of the other
reagent to make reaction
go to completion. use lim-
iting reagent to see how
much product we will get.
*percent yield*: actual
, UCSB CHEM 6AL Final Exam
Study online at https://quizlet.com/_j58lf1
yield/theoretical yield X
100. If you expect 10 g
but only get 8.4, your %
yield is 84%. get theoret-
ical yield by taking lim-
iting reagent and seeing
how much product can be
made by LR. convert g to
mol of LR, then convert
mol of LR to mol of prod-
uct; use molar ratio for
this. then convert the mol
of product by multiplying
molar mass of product.
4. distillation: ideal liquids/Raoults law *ideal liquid*: a liquid that
in incompressible (densi-
ty is constant), irrotation-
al (no turbulence, flow is
smooth), and nonviscous
(fulid has no internal fric-
tion). they do not exist in
nature. Does not change
composition by mixing. it
obeys Raoult's law for all
compisitions.
*Rauoults Law*: shown in
picture. total pressure can
be found by adding up
partial pressure; partial
pressure can be found
