Question

consider the following liquids with similar molar masses and at the same temperature.
predict which liquid has the weakest intermolecular attraction based on surface tension data.

• butyl alcohol (surface tension = 25 dynes/cm)
• propionic acid (surface tension = 27 dynes/cm)
• ethyl formate (surface tension = 24 dynes/cm)
• propyl chloride (surface tension = 18 dynes/cm)
• ethyl ether (surface tension = 17 dynes/cm)

Explanation:

Step1: Recall relationship between surface tension and intermolecular forces

Surface tension is directly related to the strength of intermolecular attractions. Lower surface tension indicates weaker intermolecular forces.

Step2: Compare surface tension values

We have the surface tension values: butyl alcohol (25 dynes/cm), propionic acid (27 dynes/cm), ethyl formate (24 dynes/cm), propyl chloride (18 dynes/cm), ethyl ether (17 dynes/cm).

Step3: Identify the lowest surface tension

Among these, ethyl ether has the lowest surface tension (17 dynes/cm), so it has the weakest intermolecular attraction.

Answer:

ethyl ether (surface tension = 17 dynes/cm)