Characteristics of water

2000/06/01 Roa Zubia, Guillermo - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena

The water we receive from the tap of the house, like the one carrying the river or the sea, is not only water, but a mixture of water mostly. But it has many other ingredients. And it is that if only H 2O would not be drinkable. We can divide the water components into groups.

Molecules H 2 O

Water molecules are molecules with very special chemical characteristics. The most remarkable can be the way to associate. When solidifying form structures ordered, increasing the volume. In addition, it has a specific high heat. This means a huge storage capacity of heat. This has made water an essential element for life. Finally, we must remember that, although to a small extent, the reaction is pH 2 O + H 2 O H 3 O + OH - H 3 O +, with a different pH concentration depending on the chemical medium.

Dissolved ions

One of the main characteristics of water is the presence of ions. They are species abandoned by the erosion of mineral salts. The dissolved substances are electrostatically neutral and dissolve in ions (charged molecular parts). Cations (normally metals) and anions are formed.

Metals and metals Metals

In general, metal concentrations are low. However, the influence of certain metals, especially heavy metals, can be high, although in small quantities. It is a variable dependent on the geological medium of the source in nature. The cations dissolved in water can give color or smell to water. However, its effects on health are notorious.

Water with large amounts of calcium and magnesium is called hard. This type of water is collected from the environment where the limestone is found. In marine waters, the amounts of sodium and potassium abound, but can also be found in many other sources. The potabilization of water with high concentration of iron, manganese or other metals usually requires special treatments.

It highlights the presence of metals in large part of water pollutants. Mercury, cadmium, lead and arsenic are the most dangerous. However, they are essential elements for certain ecosystems. For example, in some deep sea areas there are large concentrations that are essential for local life.

Anions Anions

Together with cations, anions give electrical conductivity to water. Therefore, the conductivity of the water samples is measured. Concentrations also depend on the geological medium. There are two types of anions, oxoanions (with oxygen atoms) and simple anions. In water sulphates, bicarbonates, nitrates and phosphates are typical oxoanions. The most common simple anions are chlorides and fluorides.

Organic matter Organic matter

Many bacteria and monocellular beings live in the water. Otherwise, there are small concentrations of organic molecules free of all kinds, including non-soluble ones. Despite not having a high percentage of weight, they can have a great influence on health. Therefore, water is an essential element for its consumption or treatment.

Gas dissolved

When in contact with air, natural water contains oxygen, carbon dioxide and other dissolved gases. Some of them have a great influence on chemistry and biology within water. For example, oxygen creates an oxidizing medium and carbon dioxide is essential for beings who have photosynthesis.

The origin of water characteristics in nature, therefore, should be sought in the biological and geological environment.