HW 6A
1. Identify the most important types of intermolecular forces present in solids of each of the
following substances:
a. BaSO4
e. P4
b. Ar
f.
NaNO3
c. C2H6
g. HF
d. CsI
h. CO
2. Predict which substance in each of the following pairs would have the greater IMFs:
a. CO2, OCS
b. SeO2, SO2
c. CH3CH2CH2NH2, H2NCH2CH2NH2
d. CH3OH, H2CO
3. Consider the following electrostatic potential diagrams. Rank the compounds from lowest to
highest boiling point and explain your answer.
4. In each of the following groups of substances, pick the one that has the given property. Justify
your answer.
a. Highest boiling point: HBr, Kr, CL2
b. Highest freezing point: H2O, NaCl, HF
c. Lowest vapor pressure at 25°C: Cl2, Br2, I2
d. Lowest freezing point: N2, CO, CO2
e. Lowest boiling point: CH4, CH3CH3, CH3CH2CH3
f.
Highest boiling point: HF,HCl, HBr
5. The shape of the meniscus of eater in a glass tube is different from that of mercury in a glass
tube. Why?
6. Explain why water forms into beads on a waxed car finish.
7. Hydrogen peroxide (H2O2) is a syrupy liquid with relatively low vapor pressure and a normal
boiling point of 152.2°C. Rationalize the differences of these physical properties from those of
water.
8. Carbon diselenide (CSe2) is a liquid at room temperature. The normal boiling point is 125°C and
the melting point is -45.5°C. Carbon disulfide (CS2) is also a liquid at room temperature with
normal boiling and melting points of 46.5°C and -111.6°C respectively. How do the strengths of
the intermolecular forces vary from CO2 to CS2 to CSe2? Explain.