ws
Name
16,88!
propanone ("acetone")
(this is a ketone)
2-propanol ("i sopropanol ")
butane
La, Draw a picture of each molecule, including all H's and lone pairs. Show correct geometry at any oxygen atoms
b. Classify each molecular as polar or nonpolar.
c, Which of the above molecules is the most polar, and which is the least polar? Explain,
d. For any polar molecules you drew, draw a second molecule of the substance, lined up so that it can be attracted to
the other molecule of the same substance, and show ô+/ ô- symbols,
e. Attractive Forces between molecules are often called "cohesive forces" or "intermolecular forces," [f intermolecular
attractive forces are particularly strong, does this lead to relatively high or low boiling point?
f, Propanone,2-propanol, and butane have boiling points (in'C) of, 56,82, and -1, respectively
How does polarity affect intermolecular forces and boiling points?
g.
Is water polar or nonpol ar?
h, Which of the above compounds would you expect to be soluble in water?
Which would you expect to be non-soluble in water?
i.
Gasoline is a mixture is hydrocarbons, for example CsHrz, CoHo,CsHrs, CsHzo, CnHzc
gasoline
polar or nonpo lar?
Is
Which of the above compounds would you expect to be most soluble into gasol ine?
j.
Hydrocarbon
Methane CH*
Ethane CrH,,
Propane C.H,
Butane CaH,¡
Pentane CrH,,
Hexane C,,H,a
Normal Boiling Point ("C)
-l6l
.7
-88.6
-42,t
-0.5
3ó.1
68,7
Heptane C7H¡,,
98,4
Octane CRHrs
Nonane CuHru
Decane C,nH,
t25.7
150.8
l'74.0
2. Use the data given (above) to answer these questions, (fill in with "increases" or "decreases")
a. For a given polarity, as the size and surface area of the compound increases, the boiling point
b, Therefore, as the size and surface area of the compound increases, the strength of the intermolecular forces
(or "cohesive forces")
3.
Boiling Point
Substance
{ L-l
methanol
64
ethanol
'18
l -propanol
9'7
1-butanol
tt'l
l-pentanol
138
1-hexanol
157
lJreptanol
179
Solubility in water
lmoles comoound oer 100 s H'O)
miscible*
miscible
miscible
0.1 I
0.030
0.0058
0.0008
* lltwo compounds are miscible with each other, they can dissolve together in any proportions.
a. Draw a picture showing
a solution of methanol dissolved in water.
Show at least one methanol, and several water molecules, oriented correctly
Show ò + and ô- symbols on your methanol and on at least one water.
b. Explain why
methanol is so soluble in water!
c. Draw the dot stiucture of'l-heptanol, including all H's and lone pairs:
d. Label the "polar" and "nonpolar" patts on the picture you drew:
e. Consider the data for the 7 alcohols in the table,
(l)
How is does the length of the carbon chain affect the intermolecular forces and the boiling point of the alcohols?
(2) How does the length of the
carbon chain affect the alcohol's solubility in water? EXPLAIN WHY!
c\
coàøae/
4. a. Draw polarity arrows on all polar bonds on morphine and novocaine.
b. Explain why morohine is more soluble into water than heroin,
(Note, the lone pairs are not shown on these pictures.)
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5.
The hormones estradiol , progesterone, and testosterone are shown above.
a. V/hich molecule is more polar: testosterone or
Explain your answer (refer to the structures of each molecule!)
,l
b. Which molecule is more polar:
testosterone or estradiol
Explain your answer (refer to thd structures of each molecule!)
of 126"C,155'C, and22I'C.
progesterone- testosterone
Which hormone has which melting point? estradiol(Assume that since the molecules are similar sizes, you only need to compare their polarities to answer this),
c. These hormones have melting points
Boiling Point
6.
Substance
Solubility in water
lsrams comoound oer 100 e HzO)
t"c),
butanaldehyde
ethanaldehyde
pentanaldehyde
propanaldehyde
(The above aldehydes are listed in alphabetical order.)
a. Draw the Lewis Dot structure, including all H's
and lone pairs, for propanaldehyde.
Label any polar bonds with the polarity arrow and ô*/- symbols
The 4 compounds have these boiling points, in "C: 21, 49,76, and 128,
And these solubilities, in grams compound per 100 g H2O: less than 1,3.7,20, miscible.
Fitt in the blanks in the chart: Determine whioh compound has which boiling point and which solubility.
c. On your picture ofpropanaldehyde, above, draw 3 water molecules near the propanaldehyde, oriented to be attracted
to the propanaldehyde.
b,
7. a. Draw the compound benzoic
(Hint: it
acid:
has 7 carbons total, and contains a benzene ring).
b. Draw the structure of the compound that would form,
if benzoic acid reacted with ethanol.
9.a.
b.
plus water
Ethanoic (acetic) acid and 2-pentanol can react to form a/an
that forms:
picture
compound
of
organic
the
and
draw
the
Draw structures of the acid and alcohol,
product:
2-pentanol
ethanoic acid
c.
d.
Which would be more soluble into water: ethanoic acid, or the organic product that formed?
2-pentanol can dissolve somewhat into water AND it can dissolve somewhat into hexane,
Explain why 2-pentanol is capable of dissolving into either liquid'
H
\
H-NJ
2-aminohexane
10.
t+
{-H
H
octyl amine:
(or "l-amino octane")
I
a
I
-octanol:
(aka "octyl alcohol")
a. frll in the structures for octyl amine and l-octanol.
b. Draw polarity arrows on all polar bonds on all four compounds,
c.
Circle the substance that you would expect to be more soluble into water:
1,6 hexane
octyl
or
diamine
l-octanol
2-amino hexane
or
2-amino hexane
or
octane (not pictured)
amine
1-octanol
or
l-octanol
or
octanaldehyde(not pictured)
l-heptanol (not pictured)
d. Circle the substance that you would expect to have a higher boiling point:
2-aminohexane
or
octyl amine
diamine
or
2-aminohexane
or
l-octanol
1,6 hexane
octyl
r
í
amine
l-octanol
or
l-octanol
ot
octanaldehyde(not pictured)
l-octanol
or
l-heptanol (not pictured)
octane (not pictured)
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