Surface tension of liquids

The cohesive forces in a liquid generate tension on its surface, the so-called surface tension. A metal ring that is plunged into a liquid is withdrawn from the liquid. At a certain tensile force, the liquid film will be disrupted from the ring. Based on the tensile force and ring diameter, the surface tension of a liquid can be calculated

Benefits

• High sensitivity measurement possible thanks to ring method
• Analogue set-up that can also be used as a demo experiment in the lecture hall
• Interdisciplinary use also in applied sciences or physical chemistry

Task

Examine the surface tension of a liquid.

Learning objectives

• Wetting and non-wetting liquids
• capillarity