Factors affecting Surface Tension
Surface tension is affected by several factors, some of them are discussed below-
Temperature
As the temperature increases, the surface tension of a liquid decreases, because on increasing temperature, kinetic energy of the particles breaks the intermolecular forces at the surface.
Impurities
Presence of impurities can either increase or decrease the surface tension depending on their nature. Highly soluble substance like sodium chloride when dissolved in water, increases the surface tension of water but the sparingly soluble substances like phenol when dissolved in water, decreases the surface tension of water.
Nature of liquid
Liquids having stronger intermolecular forces have higher surface tension than those having weaker forces.
Electrolytes
Electrolytes can increase or decrease surface tension depend on the ions present and their concentration. Small ions with high charge density increase surface tension.
Presence of external fields
External fields like electric or magnetic fields can also affect the surface tension of a liquid.
Presence of Dissolved Gases
Dissolved gases in liquid can also change its surface tension. Carbonated water and non-carbonated water have different surface tension.
Surface Area and Shape
Surface tension can also be affected by the shape and curvature of the surface. Small droplets have higher surface tension due to the greater curvature.
