The 15 physical and chemical properties of water

A summary of the fundamental properties of water as a substance composed of molecules.

Water is undoubtedly one of the most important elements for us, so much so that all life as we know it would not have been possible without its existence. to us, so much so that all known forms of life would not have been possible without its existence. It is part of each and every cell in our body, and we must drink it frequently in order to survive.

The importance of water is paramount, but beyond that, the fact is that this element has different properties of scientific interest. That is why throughout this article we are going to see a brief exposition of some of the main physical and chemical properties of water. 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 of them well known by most people and others more technical and less taken into account.

1. It is colorless

Although when we see the sea or a river it may seem to us that the water may have a bluish-greenish or sometimes brownish color, this is due to the way it reflects light and to the fact that it absorbs short wavelengths more easily. absorbs short wavelengths more easily (so it is easier for it to (which makes it easier for it to appear in bluish tones to our eyes). 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 that, unlike other substances, does not have a specific taste or smell. If water tastes like something, it has been adulterated in some way. (e.g. by adding flavorings) or because it has carried particles of other elements (e.g. fruits or other foods, minerals, lime, plastic or pollutants) with it when it reached us.

3. It is found in nature in all three states.

There are many substances that are difficult to find in nature beyond a specific state of matter. However, in the case of water we can easily observe it in any of the states: liquid water in the seas, rivers and rain, in gaseous form it can be observed as water vapor and in solid form it can be found as ice and snow.

4. It has a fixed transformation temperature

Although water can be mixed with other substances, the fact is that at a physical level we can see how water can be mixed with other substances. at a physical level, we can see how this element always evaporates or freezes at the same temperature.The freezing point is at 0ºC and the boiling point is at 100ºC.

5. Compound and not element

Although since ancient times water has been thought of as one of the basic elements, the truth is that, as its chemical formula, H2O, indicates, it is not an element in itself but a compound in which each molecule is made up of two hydrogen atoms bonded to an oxygen atom.

6. It is a solvent

Perhaps the word solvent is usually used at a popular level for other types of substances, but the truth is that at a chemical level water does act as a solvent. And the fact is that many substances dissolve when they come into contact with H2Owater is capable of changing their structure and properties.

In fact, it is an almost universal solvent for polar substances (i.e. substances whose molecules have a positive pole at one end and a negative pole at the other), such as alcohol or salts. Outside of laboratory chemical reactions, this property is indispensable to explain, for example, the functioning of living cells in our organism.

7. It has a neutral electrical charge

The atoms of a water molecule have a neutral electrical charge, although this does not mean that its components have no charge, but that it is generally balanced. In general, each molecule consists of ten or so protons and electrons, in which the electrons are concentrated near the oxygen. Thus, around the oxygen the electric charge tends to be somewhat more negativewhile near hydrogen it is more positive.

8. Stable density

Just as the freezing and boiling points are usually fixed, water is also characterized by maintaining a very stable density regardless of its environmental situation. A pure water without any other components (i.e., distilled) has a density of 1 kg/l.

However, normally when it is in a 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 usually 0.917 kg/l.

9. Difficult to compress

Compressing a given volume of water is highly complex (although not impossible), since this substance has a high level of cohesion (i.e. its molecules have a high capacity to remain bound together due to the strong bond they make).

10. Adheres

Water wets. This phrase, although it may seem obvious and even ridiculous, is telling 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 of someone who has been electrocuted to death or suffered a domestic accident when water came into contact with an electrical element. As most people know, these types of accidents are very real and dangerous.

However, it must be taken into account that it is not really the water itself that is responsible, but the different salts and other components in the water. the different salts and other components that it carries with it.. In fact, distilled or pure water is not an electrical conductor but an insulator, since it has no free electrons that can conduct electricity.

However, it is important to note that we are talking about distilled water in which there is nothing more than water molecules: the water we drink, with which we shower and bathe and the water we find in rivers and seas does conduct electricity as 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, its pH ranging between 6.5 and 8.5 (a totally neutral pH would be 7). This means that water can generally be either slightly acidic or slightly basic. can be slightly acidic or slightly basicbut unless its degree of acidity is manipulated or it is mixed with other substances, pure water molecules are usually practically neutral.

13. It participates in many chemical reactions

Another aspect of water to take into account 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 already seen, it is capable of dissolving polar substances, as well as reacting with basic oxides and acids to form compounds such as calcium hydroxide or sulfuric acid. Also can also generate various reactions on different types of metals, and is involved in processes such as oxidationIt is also involved in processes such as oxidation or the creation of hydrates.

14. High surface tension

This property refers to the force necessary to overcome the force of attraction between water molecules at the surface..

Its high value (in the case of water it has a value of 72.8 dyne/cm) means that generally when we are in front of a calm water surface it tends to remain stable, something that makes it difficult to break its shape if a considerable force is not applied. This is why leaves or other objects tend to float on top without generating an excessive alteration in the shape of the surface.

15. Regulates temperature

Another interesting and well-known property of water is its ability to regulate temperature. Water is able to retain heat, which causes it to cool more slowly than other substances. It also takes longer to heat up. An example of this is the effect of the sea on the temperature of the coast, which is generally more moderate than inland.