Chapter 12, Problem 69A

Interpretation Introduction

Interpretation:

The reason for water to have a higher surface tension than benzene (non-polar) needs to be explained.

Concept introduction:

Surface tension is defined as the tension of surface film of liquid which is due to the attraction of particles on the surface by liquid particles of bulk. This attraction tends to minimize surface area.

Answer to Problem 69A

Water has a higher surface tension due to strong intermolecular forces than benzene.

Explanation of Solution

Water molecules are polar in nature thus, they have strong bonding. Also, due to the difference in electro negativity of O and H, water molecules show intermolecular H bonding. Due to these strong intermolecular forces, water has higher surface tension. In benzene molecules, due to non-polar bonds, the intermolecular forces are comparatively weak. Due to weak intermolecular forces, benzene has a lower surface tension as benzene molecules on the surface do not experience any force of attraction by bulk molecules.

Conclusion

Thus, water has a higher surface tension due to strong intermolecular forces than benzene.