How determine the surface tension of liquid using capillary rise method?

The surface tension of a liquid can be determined using the capillary rise method by measuring the height to which the liquid rises in a capillary tube. The surface tension can be calculated using the following equation:

$$ γ = ρghr / 2cosθ $$

where:

* γ is the surface tension in N/m

* ρ is the density of the liquid in kg/m³

* g is the acceleration due to gravity in m/s²

* h is the height of the liquid in the capillary tube in m

* r is the radius of the capillary tube in m

* θ is the contact angle between the liquid and the capillary tube in degrees

To determine the surface tension of a liquid using the capillary rise method, the following steps can be followed:

1. A clean capillary tube with a known radius is placed vertically into the liquid.

2. The liquid will rise in the capillary tube to a certain height.

3. The height of the liquid in the capillary tube is measured using a ruler or other suitable instrument.

4. The density of the liquid is determined using a pycnometer or other suitable method.

5. The contact angle between the liquid and the capillary tube can be determined using a goniometer or other suitable method.

Once the values for γ, ρ, h, r, and θ have been determined, the surface tension of the liquid can be calculated using the above equation.