2.4 Propiedades fisicoquímicas del agua (adhesión, cohesión, tensión superficial y capilaridad)

Physical and Chemical Properties of Water

This section discusses the physical and chemical properties of water, focusing on adhesion, cohesion, surface tension, capillarity, and their significance in various contexts.

Adhesion and Cohesion

• Adhesion is the attraction between molecules of different types. Water exhibits strong adhesion forces when interacting with other molecules with positive or negative charges.

• Cohesion refers to the attraction between molecules of the same type. Water's high cohesion is due to its ability to form hydrogen bonds, allowing it to adhere to surfaces.

Surface Tension

• The difference between adhesion and cohesion is evident when comparing water and mercury behaviors on surfaces. Water spreads due to higher adhesion forces, while mercury forms droplets due to stronger cohesion.

• Cohesion creates surface tension, enabling water to resist breaking when under tension. This property allows water to form spherical droplets and supports insects walking on water.

Capillarity

• Capillarity depends on both adhesion (water-glass interaction) and cohesion (water-water interaction). It involves the rise or fall of water within narrow tubes like capillaries.

• In plants, capillarity aids in distributing water from roots throughout the entire plant structure.