8.8.5. Capillary Effect

Try these first

1. 1.

   What is capillary action?

   Hint

   Think about how water behaves in a straw.

2. 2.

   Define surface tension.

   Hint

   Consider what happens when you try to float a paperclip on water.

3. 3.

   What causes the rise of liquid in a capillary tube?

   • Gravity
   • Surface Tension
   • Atmospheric Pressure

   Hint

   Consider what holds the liquid against gravity.

4. 4.

   True or False: Capillary action occurs only in solid tubes.

   • True
   • False

   Hint

   Think of the example of a thin fabric soaking up water.

5. 5.

   A capillary tube with a diameter of 1mm contains mercury. If the surface tension is 0.485 N/m, calculate the height of mercury rise.

   Hint

   You will need the density of mercury and gravitational acceleration to solve.

6. 6.

   How does the introduction of a non-wetting fluid (like oil) into a capillary tube with water affect the capillary rise?

   Hint

   Consider the properties of the fluids involved.