Question

It is said that a liquid rises or is depressed in capillary due to the surface tension. If a liquid neither rises nor depresses in a capillary, can we conclude that the surface tension of the liquid is zero?

Answer 1

Answer:

What if a liquid neither rises nor becomes depressed in a capillary tube, can we conclude the surface tension vanishes?

• No. If the cohesion of the liquid's meniscus is precisely equal to the adhesion of the capillary tube walls, the liquid surface will remain at the hydro-static fluid level

Answer 2

The surface tension of the liquid is not zero.

Explanation:

• When the cohesion of the meniscus of the liquid is exactly equal to the adhesion of the capillary tube walls, the liquid surface shall remain at the level of hydro-static fluid.

• If the surface tension is greater or less: the meniscus becomes convex and the force of the surface tension depresses the liquid; or It will become concave and increase the surface tension force of the liquid, respectively.

• I assume all the pressurized liquids have a certain surface tension, which helps to bind them together the surface tension would disappear into a vacuum, and the liquid would become a gas.