Description

To measure the surface tension of a liquid by observing the formation and detachment of air bubbles through a capillary from an adjustable pressure system. Comprises a Jaeger’s tube (capillary tube) connected to a stopcock and air supply fitted into a rubber stopper and mounted in a 250 ml Erlenmeyer flask. U-tube vertical manometer tube fixed to a wooden stand graduated scale in millimeters adjustable with clamping screws to zero the liquid level. High-quality rubber tubing to connect the air chamber to the manometer and Jaeger tube. Manual air control via rubber hand pump or syringe bulb allows gradual increase of air pressure until bubble detachment occurs. Glass beaker placed under the Jaeger tube to collect the outflowing liquid or air bubble. Mounted on heavy wooden base with mounted vertical support providing stability during experimentation.

Working Principle:

• Based on Jaeger’s method, surface tension is determined by the pressure required to form an air bubble at the tip of a submerged capillary.
• The pressure at which the bubble just detaches is recorded from the manometer.

Formula Used: 
T=r?h???g2T = frac{r cdot h cdot rho cdot g}{2}T=2r?h???g?
Where:

TTT = Surface tension

• rrr = Radius of the capillary tip
• hhh = Pressure head from manometer
• ?rho? = Density of the manometer liquid
• ggg = Acceleration due to gravity