Surface Tension Force Explained
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible.
This phenomenon arises due to the cohesive forces between liquid molecules.
Understanding Cohesion vs. Adhesion
- Cohesion: The attraction between molecules of the same substance. Within a liquid, molecules are pulled equally in all directions by neighboring molecules. However, at the surface, molecules lack neighbors above them, leading to a net inward pull.
- Adhesion: The attraction between molecules of different substances.
The net inward pull experienced by surface molecules, caused by the stronger attraction to molecules within the liquid (cohesion), creates tension along the surface. This cohesive force is the primary reason for surface tension.
Therefore, surface tension is caused by the force of cohesion at the free surface.
Important Questions from Surface Tension
Falling drops of rain break up and coalesce with each other and finally achieve an approximately spherical shape in the steady state. The radius of such a drop scales with the surface tension σ as
The property of a fluid which enables it to resist tensile stress is known as
Above the critical micelle concentration (CMC), the option which correctly describes the variation of molar conductivity with increase in concentration of sodium dodecylsulphate în aqueous solution is
If the surface tension of the soap bubble is 0.035 N/m, then the work done in blowing the soap bubble of radius 5 cm in the air is.
Addition of detergent to liquid
