Distilled water is a chemical compound consisting of two hydrogen atoms and one oxygen atom. The molecule of this substance is chemically indicated by the formula H 2 O. As a result of the distillation process, all impurities and ions are removed from the water. The special properties of distilled water are considered in the article.
The importance of water for humans
About 65% of water is in the human body. This substance is more important for human life than food, because without food a person can maintain his vital functions for several weeks, and without water a person’s life ends in a few days.
Water performs the following functions in the body:
- the supply of nutrients to cells and the removal of decay products from them;
- help in the digestion process, which consists in the formation of gastric juice;
- constant hydration of the skin, eyes, mouth, nasopharynx and joints;
- regulation of body temperature and metabolic processes in the body.
Drinking enough water per day helps prevent the following conditions:
- diabetes;
- hypoglycemia;
- arthritis;
- dry skin
- obesity and some others.
If a person loses 20% of his body’s water, then immediate death occurs.
What is distilled water, what physical properties does it have
Distilled water is a liquid substance consisting only of H 2 O molecules. It is obtained as a result of a distillation process, which consists in the separation of liquid components in a mixture.
The physicochemical properties of distilled water differ from those for ordinary water, which a person drinks daily. This difference is due to the high purity of distilled water. For example, if we talk about such a physical property as electrical conductivity, then it is practically zero. In distilled water there are no current carriers, which in ordinary water are ions of chlorine, calcium, magnesium and fluorine.
Note that the H 2 O molecule itself is electrically neutral, and therefore cannot participate in the formation of an electric current. In fairness, we note that the ionic product of water, that is, the product of molar concentrations of H + and OH - ions is 10 -14 , that is, in one liter of water there are 10 -7 mol of atoms of each of these ions. However, this concentration is too low to create a practically noticeable electric current.
It should be noted another phenomenon that relates to such a physical property of distilled water as boiling. The process is associated with the presence in the substance of impurities and various macroscopic particles. In the case of distilled water, there are no such particles, so the liquid can be heated much higher than 100 ° C, and it will not boil. If salt or sugar is added to such "overheated" water, or simply start stirring water, then it will begin to boil explosively.
Distillation process
This process for water treatment has been used since ancient times. The essence of the distillation process by evaporation is that water boils in a sealed vessel (distiller), its vapors rise and fall into a special container called a condenser. Here, the substance again passes from the gaseous to the liquid phase as a result of cooling. The end result of the distillation process is purified water from impurities in the condenser and the remaining precipitate in the distiller.
The liquid obtained by this method does not have 100% purity, since a small amount of impurity particles is carried along with the vapor during the evaporation process.
Note that such a method of water distillation will be useless if there are impurities in the source water, which will also turn into a gaseous state during boiling, for example, alcohols.
Distilled water and its pH
If we talk about the chemical properties of distilled water, then first of all it should be said about its pH. The pH, or pH, is mathematically defined as the negative decimal logarithm of the molar concentration of hydrogen cations. If the pH value is> 7, then we speak of an alkaline environment, if pH <7, then we are talking about an acidic environment.
Ordinary water has a slightly acidic environment, while for distilled water, pH = 5.8. The reason for this acidity of pure water is that a large amount of carbon dioxide is dissolved in it.
When dissolved in distilled water, carbon dioxide forms a carboxylic acid by the following chemical reaction: 2H 2 O + CO 2 -> H 2 O + H 2 CO 3 .
In solution, in reality, there is an ammonium cation H 3 O + and an anion of hydrogen carbonate HCO 3 - . The process of saturation with carbon dioxide of the newly obtained distilled water, which has a pH = 7, occurs in 1-2 hours.
It should also be noted that the pH of ultrapure water is difficult to measure, since the physicochemical property of distilled water, such as electrical conductivity, is practically zero, which greatly distorts the results of special instruments for measuring acidity - pH meters.
Bidistilled water
Such water is obtained as a result of a double distillation process. Such a liquid is often called chemically pure. If the results of measurements of the purity of bidistilled water are unsatisfactory, then the distillation process is applied again to it.
It is mainly used as a solvent for medications for parenteral administration. It is also used for the preparation of hypoosmolar solutions for intravenous or intramuscular administration.
Distilled water
Water is a vital substance for man and for life on the planet as a whole. After all, it is considered a universal solvent and is widely used in all spheres of human activity. However, for its use, water must have a certain level of quality. The distillation process is one way to improve water quality.
Most often, distilled water is used in the following processes:
- Direct human consumption. The beneficial properties of distilled water are that it does not contain various harmful impurities in its composition. In the hot season, people drink this water with ice cubes. Since it does not contain impurities, its freezing temperature exactly corresponds to 0 ° C. Note that the physicochemical properties of distilled water after freezing and subsequent defrosting are preserved.
- Chemistry. Distilled water is used to work with various reagents in the laboratory.
- Industry. Pure water is used in the production of cooling drinks, as well as in boilers, thereby avoiding the formation of scale in them.
- In almost all medical processes.
Possible problems with drinking distilled water
Distilled water does not contain impurities that are present in ordinary water. Some of these impurities may be useful, for example, fluorine anions, which are specially added to a liquid to prevent tooth decay. Therefore, the constant use of distilled water can significantly increase the risk of its formation.
Calcium and magnesium ions are useful for human health, therefore, it is recommended to compensate for their absence in distilled water by the use of other foods.