Question

How to determine the surface tension of water by capillary rise method observations?

Answer 1

Three capillary tubes of different radii and a tipped pointer clamped in a metallic plate with a handle, travelling microscope, clamp and stand, a fine motion adjustable height stand, a flat bottom open dish, clean water in a beaker, thermometer.

Answer 2

Surface tension is a cohesive force acting between liquid molecules.

Capillary action can be defined as the rise of liquid inside the tube which has very small diameter which is already immersed in a liquid.

The smaller the diameter of the tube, the higher the liquid rises.

Using the formula,

T=$\frac{r(h+\frac r3)\rho g}{2\cos\ cos\ \theta}$  

The r: inner- radius of the capillary tube.

h: height of the liquid rise.

ρ: density of the liquid used.

G: acceleration due to gravity.

Θ: angle of contact made with the tube by the water.