Properties of water and hydrogen bonding

Describe the structure of a water molecule.

A water molecule is shaped like a wide V, with two hydrogen atoms bonded to an oxygen atom by single covalent bonds. This shape and the unequal sharing of electrons make it a polar molecule.

What is cohesion, and how does it result from hydrogen bonding in water?

Cohesion is the phenomenon where water molecules stay close to each other due to hydrogen bonding. These bonds create a structured network, making water more organized than most other liquids.

How does cohesion contribute to water's high surface tension?

Cohesion due to hydrogen bonding gives water a high surface tension, making it difficult to stretch or break its surface. Water molecules at the surface form an ordered arrangement, bonding to each other and the water below but not to the air.

Give an example of how water's surface tension can be observed in everyday life.

Water’s high surface tension allows spiders to walk on water without breaking the surface and can be seen when a drinking glass is overfilled, with water standing above the rim due to cohesion.

Describe how cohesion aids in the upward transport of water in plants.

In plants, cohesion allows water to be pulled upward from roots to leaves. As water evaporates from a leaf, it pulls on molecules below, creating an upward force that is transmitted through the plant’s water-conducting cells.

What role does adhesion play in water transport in plants?

Adhesion is the attraction between water and other substances. In plants, adhesion of water to cell walls helps resist the downward pull of gravity, supporting the upward movement of water.