Name _____________________________________________ Date ____________________ Period ________
Properties of Liquids
1. Identify the most important types of intermolecular forces present in of each of the following substances.
Circle the molecule with the highest boiling point in each pair.
a. CH3OH
____________________
CH3SH
____________________
b. CH3OCH3
____________________
CH3CH2OH
____________________
c. CH4
____________________
CH3CH3
____________________
d. CO2
____________________
NO21-
____________________
2. Identify the most important types of intermolecular forces present in of each of the following substances.
Circle the molecule with the higher vapor pressure at a given temperature in each pair.
a. Br2
____________________
I2
____________________
Explain your reasoning. _________________________________________________________
b. H2S
____________________
H2O
____________________
Explain your reasoning. __________________________________________________________
c. NH3
____________________
PCl3
____________________
Explain your reasoning. _________________________________________________________
d. CH3OH ____________________
H2CO ____________________
Explain your reasoning. _________________________________________________________
3. Which compound would you expect to have greater surface tension:
a. Acetone
b. Water
Explain why in terms of intermolecular forces.
4. Which substance is more volatile? Explain your answer.
a. H2O
b. NH3
c. CH4
5. You have three covalent compounds with three very different boiling points. All of the compounds have
similar molar masses and relative shape. Explain how these three compounds could have very different
boiling points.
6. Use the vapor pressure graph to answer the following questions.
a. What is the vapor pressure of hexane at 25oC?
_______________
b. At what temperature does heptane have a vapor pressure of 310 mmHg?
_______________
c. What are the approximate normal boiling points of pentane, hexane and heptane?
d. At a pressure of 450 mmHg and a temperature of 70oC, is each substance a liquid, a gas or a
mixture of a liquid and gas?
e. Which substance has the highest vapor pressure at 30oC?
_______________
f. Which substance has the highest intermolecular forces?
_______________
g. What type of intermolecular force is found in all of the substances?
_______________