Exercises
Exercise 1. Ethanol, C2H5OH, and dimethyl ether, CH3–O–CH3, are constitutional isomers. Which would have the higher surface tension. Explain why.
Ethanol has stronger intermolecular forces of attraction due to hydrogen bonding, therefore ethanol would have the higher surface tension.
Exercise 2. Which substance in each pair has the highest viscosity?
Both substances have only London dispersion forces. CBr4 would have the highest viscosity due to the stronger dispersion forces.
b) acetone or ethylene glycol
Ethylene glycol has stronger intermolecular forces of attraction due to hydrogen bonding, therefore ethylene glycol would have the higher viscosity.
c) pentane, CH3CH2CH2CH2CH3, or isopentane 
Pentane has the higher viscosity due to the stronger London dispersion forces. Isopentane has a CH3 branch which does not allow the molecules to get as close together, weakening the London dispersion forces.
Exercise 3. Which would have the highest viscosity, water or dimethyl sulfide, (CH3)2S. Explain.
Water has the higher viscosity due to strong intermolecular hydrogen bonding. The C–S bonds are not polar in dimethyl sulfide, therefore, there is only London dispersion forces of attraction.
Exercise 4. Water flows quickly through the narrow opening of a bottle while molasses flows slowly. Is this due to the differences in viscosity or in surface tension?
Exercise 5. Explain the differences in viscosity, surface tension, and capillarity.
Viscosity is the resistance to flow. Surface tension is the required energy to increase a surface area of a liquid. Capillarity is the movement of liquid up against the pull of gravity.