Compound Name
Propane
Propanone
1-propanol
Compound Formula
CH3CH2CH3
CH3COCH3
CH3CH2CH2OH
Change in Hvap (kJ mol-1
19.0
32.0
47.3
8. Using the information in the table above, answer the
following questions about organic compounds
• a. For propanone,
i. draw the complete structural formula
ii. Predict the approximate carbon to carbon bond angle
• i.
• ii. The approximate carbon to carbon bond angle is 120o
because the carbon to carbon bond is has the
hybridization of sp2, which has 120o bonds.
• b. For each pair of compounds below, explain why they
do not have the same value for their standard heat of
vaporization, change in Hvap (You must include specific
information about both compounds in each pair)
• i. Propane and propanone
• ii. Propanone and 1-propanol
• i. Propane has the lowest Hvap because it only has single
bonds, which are broken the most easily.
• Propanone has a double bond, which is stronger and
shorter in length than a single bond. The energy required
to break a single bond is less than the energy required to
break a double bond.
• ii. 1-propanol has the highest Hvap due to the fact that it
has a hydrogen bond (O and H), which more energy to
break than both single and double bonds.
• c. Draw the complete structural formula for an isomer of
the molecule you drew in part (a) (i)
• Given the complete structural formula for propyne below
• i. indicate the hybridization of the carbon atom indicated
by the arrow in the structure above
• ii. indicate the total number of sigma () bonds and the
total number of pi () bonds in the molecule
• i. The hybridization of the carbon atom indicated by the
arrow in the propyne is sp, as it has two bonds and no
lone pairs.
• ii. Propyne has 2 pi bonds and 6 sigma bonds
C has 4 single
bonds, and each
single bond is a
sigma bond
The carbon has
one single bond
and one triple
bond. The single
bond is 1 sigma
bond whereas
the triple bond
has 2 pi bonds
and 1 sigma
bond for the total
of 2 sigma
bonds and 2 pi
bonds