How much force is needed to break the surface tension of wat

How much force is needed to break the surface tension of water at 20 o C.

Solution

Surface Tension

The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. A thin film is formed on the water surface and due to formation of film it\'s more difficult to move an object through the surface than to move it when it is completely submersed.

Surface tension is generally measured in dynes/cm, the force in dynes required to break a film of length 1 cm. Water at 20°C has a surface tension of 72.8 dynes/cm compared to 22.3 for ethyl alcohol and 465 for mercury.