Chapter 12, Problem 68A

Interpretation Introduction

Interpretation:

The effect of strength of intermolecular forces on viscosity needs to be explained.

Concept introduction:

Viscosity is defined as the resistance of a liquid to flow. Generally, liquids such as ethanol, water and ethanol have low viscosity. These liquids flow very slowly and have a high viscosity.

Answer to Problem 68A

The viscosity is directly proportional to intermolecular forces.

Explanation of Solution

If liquids have higher viscosity; the flow of liquid will be slow. Due to the slow flow of a liquid, if the molecules move past each other, they will have minimal resistance. If the intermolecular forces will be strong, it will be difficult for molecules to flow like this. The presence of hydrogen bonding like in ethanol results in an increase in strength of intermolecular attractive forces and hence increases the viscosity.

Thus, if liquid molecules have high intermolecular forces, they will have high viscosity.

Conclusion

The viscosity is directly proportional to intermolecular forces.