Question

Give the necessary theory and method for determining the surface tension of water by capillary rise method.  

Answer 1

According to theory, the capillary rise is

$$h =\frac{ 2 σ \text{cos} θ}{ ρ g r}, \\\space\\ \sigma=\frac{h\rho gr}{2\text{cos}\theta}.$$

So, we need to measure the radius of the capillary tube r, know the density of liquid, and measure the angle theta: