How can surface tension be experimentally determined?

Surface tension can be measured with force tensiometer using Du Noüy ring or Wilhelmy plate. Or with optical tensiometer using the pendant drop method.

What is surface tension experiment?

Mix a little washing up liquid in a cup with water and gently pour into the bowl, the paperclip will sink as the water can no longer support the weight of the paper clip after the washing up liquid disrupts the surface tension of the water.

How does rubbing alcohol affect the surface tension of water?

Surface Tension of Water (at 20°C) = 72.8 mN/m Surface Tension of Isopropyl Alcohol (at 20°C) = 23.0 mN/m (Note that the actual surface tension of rubbing alcohol will be slightly higher than the value for pure isopropyl alcohol, because rubbing alcohol is 70% isopropyl alcohol and 30% water.)

What are 3 surface tension examples?

Examples of Surface Tension

  • A Drop of Liquid.
  • Soaps and Detergents.
  • Washing with Hot Water.
  • Clinical Test for Jaundice.
  • Water Striders.
  • Capillary Action.
  • Formation of a Meniscus.
  • Bubbles.

Which two methods are used for the determination of surface tension?

Some of the methods followed for measuring surface tension are as follows:

  • Capillary Rise Method.
  • Stallagmometer method.
  • Wilhelmy plate or ring method.
  • Maximum bulk pressure method.

How will you determine experimentally the surface tension of given liquid using stalagmometer?

The principle is to measure the weight of drops of a fluid of interest falling from a capillary glass tube, and thereby calculate the surface tension of the fluid. We can determine the weight of the falling drops by counting them. From it we can determine the surface tension.

What happens when you add soap to milk and food coloring?

When liquid dish soap is added to milk with drops of food coloring on the surface, the soap reduces the surface tension of the milk and reacts with the fat. This interaction causes the fat particles in the milk to move and create swirls of color.

Why does adding soap reduce surface tension?

In the process of moving to the surface, the soap molecules force apart the water molecules, and hence the water molecules no longer have hydrogen bonds with each other, and the surface tension is weakened.

What factors affect surface tension?

Surface tension is caused by the effects of intermolecular forces at the interface. Surface tension depends on the nature of the liquid, the surrounding environment and temperature. Liquids where molecules have large attractive intermolecular force will have a large surface tension.

What is unit of surface tension?

Newton per metreSurface tension / SI unit