CHEM 104 The Lower Boiling Point & Lower Intermolecular Interactions Worksheet

Chem 104NAME_________________________
Homework #9
Due Monday Apr 18, 2022
1 atm = 760 mm Hg = 760 torr = 14.7 ps
K = °C + 273
R = 0.0821 L*atm/mol*K
PV = nRT
1 mole gas at STP has V=22.4 L
1. T/F _____London dispersion forces are exhibited by all covalent compounds.
2. Predict whether CH4 or CH3OH will have the lower boiling point. Explain. (Hint: consider
the relative strengths of the intermolecular interactions of the two compounds.)
3. A birthday balloon contains helium at a pressure of 851 torr. What is this pressure in
units of mm Hg?
4. A sample of neon gas has a volume of 7.2 mL at a pressure of 1.50 atm. What is the
pressure exerted by the gas if the volume is increased to 28.8 mL, at constant
temperature?
5. A volume (54.2 L) of gas at 115 K is heated to 345 K, at constant pressure. What volume
does the gas now occupy?
6. A balloon that contains 0.500 L of helium at 25 °C is cooled to 11 °C, at a constant
pressure. What volume does the balloon now occupy?
7. How many moles of gas are contained in a scuba diver’s 12.6-L tank filled with 3422 psi of
air at 25 °C?
8. A sample of gas contains four gases with the following partial pressures: He (113 mm
Hg), Ne (184 mm Hg), Ar (35 mm Hg), and Xe (445 mm Hg). What is the total pressure of
the sample?
A) 777 mm Hg B) 760. mm Hg C) 445 mm Hg D) 332 mm Hg