Water is undoubtedly one of the most important elements for us, to the point that any form of life known until now would not have been possible without its existence. It is part of every cell in our body and we need to drink it frequently to survive.
The importance of water is paramount, but beyond that, the truth is that this element has different properties of scientific interest. That’s why throughout this article we’ll be looking at a brief exposure of some of the main physical and chemical properties of water.
Physical and chemical properties of water
These are some of the properties of this element, some are well known to most people and others are more technical and less considered.
1. It is colorless
While when we look at the sea or a river, it may seem to us that the water may have a bluish green or sometimes brown color, this is due to the way it reflects light like absorbs short wavelengths more easily (This makes it easier to appear in our eyes in bluish tones). However, we cannot perceive any color in it (unless it is mixed with another substance), being transparent to our sight.
2. It has no taste or smell
Water is a substance which, unlike others, does not in itself have a certain taste or odor. In the event that water knows something to us, it is because it has been adulterated in some way. (E.g. by adding flavorings) or because when it reaches us it has entrained particles from other elements (e.g. fruit or other food, minerals, lime, plastic or contaminants ).
3. It is found in nature in all three states
There are many substances that are difficult to find in nature beyond a particular state of matter. However, in the case of water, we can easily observe it in any of the states: the liquid water of seas, rivers and rain, in gaseous form can be observed in the form of water vapor. water and solid form can be found such as ice and snow.
4. It has a fixed processing temperature
Although water can be mixed with other substances, the truth is on the physical plane, we can contemplate how this element always evaporates or freezes at the same temperature, With a freezing point of 0 ° C and a boiling point of 100 ° C.
5. Compound and not element
Although water has been considered one of the basic elements since ancient times, the truth is that, like its chemical formula, H2O, tells us, we are not dealing with an element in itself but with a compound in that each molecule is made up of two hydrogen atoms bonded to one oxygen atom.
6. It is a solvent
Perhaps the word solvent is often used at a popular level for other types of substances, but the truth is that at a chemical level water acts as such. And this is it many substances dissolve on contact with H2O, To be water capable of changing its structure and properties.
In fact, it is an almost universal solvent for polar substances (that is, among these substances, molecules have a positive pole on one end and a negative pole on the other), like alcohol or salts. Apart from laboratory chemical reactions, this property is essential for explaining, for example, the functioning of living cells in our body.
7. It has a neutral electric charge
Atoms in a water molecule have a neutral electric charge, although this does not mean that their components do not have a charge but that it is generally balanced. Typically, each molecule is made up of a dozen protons and electrons, in which the electrons are concentrated near oxygen. like that, around oxygen, the electric charge tends to be a little more negative, While near hydrogen is more positive.
8. Stable density
In the same way that freezing and boiling points are usually fixed, water is also characterized by maintaining a very stable density regardless of its environmental situation. Pure water without any other component (i.e. distilled) has a density of 1 kg / l.
Usually, however, when in liquid state at a temperature of about 20 ° C, it has a density of 0.997-0.998 kg / l. In the case of ice, its density is generally 0.917 kg / l.
9. Difficult to compress
The compression of a certain volume of water is very complex (but not impossible), since this substance has a high level of cohesion, that is, its molecules have a great ability to remain attached to each other due to the strong union they make).
The water is wet. This sentence, although it may seem obvious and even ridiculous, tells us about another of the physical properties of the liquid element: the ability to adhere to other surfaces and materials.
11. Low electrical conductivity
We have probably heard on one occasion of someone being electrocuted to death or had an accident in the home when water came in contact with an electrical element. As most know, these types of accidents are a very real and dangerous thing.
However, it should be noted that the culprit itself is not really water, but the different salts and other components that it takes with it. In fact, distilled or pure water is not a conductor of electricity but an insulator, because it has no free electrons that can conduct it.
However, it is important to note that we are talking about distilled water in which there are only water molecules: the water we drink, with which we shower and bathe and which we find in rivers. and the seas. If it conducts electricity such that it contains a large amount of minerals and other components with conductive potential.
12. relatively neutral pH
Another characteristic of water is that in general and on average it usually has a neutral or almost neutral pH, fluctuating its pH between 6.5 and 8.5 (a completely neutral pH would be 7). This implies that water in general it can be slightly acidic or slightly basicBut unless its degree of acidity is manipulated or mixed with other substances, pure water molecules are usually virtually neutral.
13. Participates in multiple chemical reactions
Another aspect to consider in water is its high level of interaction with other elements, so that it produces different chemical reactions and becomes part of different processes or substances.
For example, as we have seen, it is able to dissolve polar substances, as well as react with basic oxides and acids to form compounds such as calcium hydroxide or sulfuric acid. too much it can generate various reactions on different types of metals, And participates in processes such as oxidation or hydration.
14. High surface tension
This property refers to the force required to overcome the force of attraction between water molecules at the surface level.
Its high value (in the case of water has a value of 72.8 dina / cm) means that in general when we are in front of a calm water surface this reserve remains stable, which makes it difficult to break its shape. but considerable force is applied. Therefore leaves or other objects usually float without causing excessive alteration of the shape of the surface.
15. Set the temperature
Another interesting and well-known property of water is its ability to regulate temperature. And is the water able to retain heat, which makes it cool more slowly than other substances. It also takes longer to warm up. We see an example in the effect that the sea has on the temperature of the coast, which is generally more moderate than inland.
- Marín Galvín, R. (2010). Physical, chemical and biological characteristics of water. School of industrial organization. [Online]. Available at: https://www.eoi.es/es/savia/publicaciones/19900/caracteristicas-fisicas-quimicas-y-biologicas-de-las-aguas.
- Marín Galvín, R .; Rodriguez Mellado, JM (1999). Physicochemistry of water. Editorial Díaz de Santos.
- Félez Santafé, M. (2009). Current situation of the state of biological purification. Explanation of the methods and their foundations. Barcelona Engineering School – ET Industrial, specializing in industrial chemistry. Polytechnic University of Catalonia [Online]. Available at: http://hdl.handle.net/2099.1/6263.