The physical and chemical properties of water Make it the most important compound of the planet, which integrates the natural ecosystems being fundamental for the sustenance and reproduction of life on the planet.
Water, Vital resource for the existence of life on the planet , It is odorless, tasteless and colorless, with 97.2% being found in the seas, lakes, rivers and oceans, and the remaining 2.8% in the form of fresh water.
From the 640 century BC the Greek philosopher Thales of Miletus Affirmed that water is everything, considering it as the basic element of the universe.
In the eighteenth century they refuted Tales of Miletus, when the English chemist Cavendish, who synthesized water from a combustion of air and hydrogen, and Lavoisier , Proposed that water is not an element, but a chemical compound.
Physical and chemical properties of water
Physical properties
1- It can be found in the three states of matter
Water is a chemical compound that can be found in solid, liquid and gaseous form.
In their solid phase, the particles are tightly bonded to one another, whereby for example an ice cube can maintain its shape for a time regardless of where it is submerged.
In its solid state the water is usually in the form of ice in snowflakes, glaciers and polar ice caps.
In its liquid phase, the molecules are separated making the water can take the form of the container that contains it.
It can be found in nature as rain, drops of water, in the form of dew on vegetation and in oceans, rivers, lakes and seas.
And, in its gas phase, the molecules are totally separated and disordered, which causes the water to become gas or water vapor, being able to find it in the form of fog and vapor, as in the case of clouds.
It is thanks to this property that the processes of evaporation, condensation, sublimation, freezing, melting and volatilization exist.
These are the processes through which water leaves its liquid state to become water vapor and freeze until it falls in the form of rain or hail, leaving frost or ice and even after the heat thaw.
You may be interested Water States: Solid, Liquid and Gaseous .
2- It has stable temperature markers
The water reaches its freezing point at zero degrees Celsius and its boiling point at one hundred degrees.
Hence, while the water has a temperature higher than zero degrees and less than a hundred, it will always be in a liquid state.
3- It has a high specific heat index
This index refers to the amount of heat that a substance can absorb. In the case of water, it has a specific heat that is higher than that of any other substance, hence it can absorb large amounts of heat and its temperature descends more slowly than that of other liquids as it is releasing energy when it cools.
4- The surface tension is high
Understanding by this the amount of energy that is required to increase the surface of a liquid per unit area.
In the case of water, the molecules that form it are united and have a great cohesive force, that is why its spherical geometry obtains the maximum volume in a minimum of area.
Surface tension is the physical effect that forms a kind of hard elastic membrane in the surface layer of water that is at rest.
This allows, for example, insects to stand on water droplets without sinking or water droplets can be kept at rest while keeping their volume in a small space.
Chemical properties
5- Composition
The water is made up of one atom of oxygen and two of hydrogen, a simple molecule that has polar bonds that allow to establish bridges of hydrogen between the adjacent molecules.
This connection is of great importance as it gives water properties that allow it to have a greater mass, and reach high melting and boiling points, fundamental for the water to be in a liquid state in the earth.
6- Universal solvent
This can dissolve more substances than any other liquid. Their molecules are polar, hence they have zones of positive and negative charges.
Also, its molecules are dipolar, ie the central oxygen atom shares a pair of electrons with each of the two hydrogen atoms, which makes it a great solvent medium for ionic compounds such as minerals and carbohydrates.
This property of water is due to its ability to form hydrogen bonds with other substances, which dissolve when they interact with the polar molecules of water.
7- Its molecules have a high cohesive force
Their molecules, when attracted to each other, remain linked to one another. Having hydrogen molecules, these are responsible for holding tightly together forming a compact structure that turns the water into an incomprehensible liquid thanks to its high adhesion strength.
8- Its density is 1kg / l
This density increases as the temperature decreases, reaching a maximum density of 4 degrees.
It is because of this property that ice can float in the water, so when a lake or sea freezes the layer of ice floats on the surface insulating the rest of the mass of water preventing it from being undone.
9- Low degree of ionization,
This is because only one of every 551,000,000 water molecules is dissociated in ionic form. Therefore, the pH of the water is considered as neutral.
10- Form complex combinations
It is able to form complex combinations by joining some salts, giving rise to hydrates, substances containing water. Likewise, the water reacts with many metal and non-metallic oxides in order to form hydroxides and oxacids.
11- Generates the hydrophobic effect
It is a phenomenon that is seen when non-polar substances come into contact with water.
Hydrophobic molecules tend to aggregate and bind together excluding water molecules, a clear example of which is the fact that when water is mixed with oil the mixture is separated into an aqueous and an oily phase.
References
- Water. Retrieved on August 2, 2017 from vitalis.net.
- Azcona, A. and Fernández, M . (2012). Biological properties and functions of water . Retrieved on August 2, 2017 from ucm.es.
- Specific heat and caloric capacity . Retrieved on August 2, 2017 from corinto.pucp.edu.pe.
- Changes in the state of water in nature. Retrieved on August 3, 2017 from tutiempo.net.
- (2013). Five properties of water . Retrieved on August 3, 2017 from owlcation.com.
- Pérez, J. and Borge, M. Water: volumes and composition of body fluids . Retrieved on August 2, 2017 from unican.es.
- Properties of water . Retrieved on August 3, 2017 from homesciencetools.com.
- Properties of water. Retrieved on August 3, 2017 from lineaverdeceutatrace.com.
- Surface tension . Retrieved on August 3, 2017 from definicion.de.
- What is the hydrophobic effect? Retrieved on August 3, 2017 from curiosoando.com.
- S Department of Interior . Water properties . Retrieved on August 2, 2017 from water.usgs.gov.
- Valenzuela, L. The chemistry of water. Retrieved on August 3, 2017 from educarchile.cl.
- Water chemistry. Retrieved on August 3, 2017 from science.uwaterloo.ca.