Aqueous solution process that involves two solvents and is called strictly this way, when the largest component is water. This process is of great importance in nature and also in chemistry, be it industrial or daily chemistry or life chemistry, as it is often called.
Summary
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- 1 Origin
- 1 Biochemical and physiological functions of water
- 2 Types of dissolution
- 2 Reactions in aqueous solution
- 1 Dissolution:
- 3 General properties of aqueous solutions.
- 1 Electrolytic properties
- 4 Characteristics of solutions
- 5 External links
- 6 Sources
Origin
Water is called the millennium solvent, due to the large number of components that can be dissolved in it and its great mixing capacity. The most water soluble compounds are those of the ionic group, such as sodium chloride , and on the other hand, the least soluble are those of the covalent group, such as insoluble metals.
Water is the most abundant biomolecule of the human being , it constitutes 65-70% of the total body weight. This proportion must be kept very close to these values to maintain water homeostasis, on the contrary the organism is faced with pathological situations due to dehydration or fluid retention. The importance of studying the water biomolecule lies in the fact that all the biochemical reactions are carried out in the water, all the nutrients are transported in the water.
The types of aqueous solution are classified according to the size of the solute to be combined with the water. A process that occurs during dissolution is dispersion, which is defined as the mechanical interposition of the particles.
Salts, as we mentioned before, are an ionic compound that is easy to dissolve with water. This solution, due to the constant and high dielectric charge that the salts contain, transform the solution into a conductive solution. This is generated when the ionic salt comes into contact with the water molecules, which surround the most superficial ions. When this solution is generated, the solution may be colorless or colored, but it will always be transparent.
Biochemical and physiological functions of water
From the above it follows that the biochemical and physiological functions of water are consistent with the physicochemical properties that have been studied. Water can act as a component of macromolecules. Proteins, nucleic acids, polysaccharides, can stabilize its structure through the formation of hydrogen bonds .
The fact that it is considered a universal solvent for ionic, nonionic polar and amphipathic substances, makes it possible for all biochemical reactions to be carried out within it, as well as the adequate transport of substances in the body. Water can act as a substrate or product of many reactions such as hydrolysis or ester formation .
The thermoregulatory nature of water , allows to achieve a balance of temperatures throughout the body as well as the dissipation of metabolic heat we observe it in extensive exercise.
Types of dissolution
The correct solution is one in which the solute mixes uniformly with water, that is, it dissolves well. In case it is a solid solute, we will be facing a much more complex and slow process. As for the dissolution of salts, the most common, as we have already clarified several times, is a short process that has three stages. In the first two, the solute ions and the solvent molecules are separated, which absorb energy and form an endothermic process. In the third and last stage the interaction between the solvent and the solute occurs, and this responds to an exothermic process, that is, it releases energy instead of absorbing it.
Finally, something that we must take into account is the solubility of a component, that is, the dissolution and interaction capacity that it has. When a correct dissolution is not achieved, which can happen when we add more amount of solute than solvent, we speak of a saturated solution, since the expected interaction between the two components is not achieved.
Reactions in aqueous solution
A large number of substances are found in nature as part of various solutions or solutions.
Dissolution:
it is a homogeneous mixture of two or more substances (components). The constituent particles of a solution are atoms, molecules or ions, which, due to their small size, cannot be distinguished with the naked eye. This makes it appreciated as a uniform system, therefore, its composition is the same in all parts of the solution.
A solution can be made up of several substances, the most important from a chemical point of view are binary. The substances that make up a binary solution are called:
- Solute: it is the substance that dissolves and is the present smallest quantity.
- Solvent or Solvent: it is the medium in which the solute dissolves and is the substance present in the greatest quantity.
The solutions are usually classified according to their physical state, a solution can be:
- Fizzy: both the solute and the solvent is a gas (air, natural gas such as methane)
- Liquids: the solute can be a gas, a liquid or a solid and the solvent a liquid. In the first case, there are carbonated drinks and oxygen in water; in the second case, there are gasoline and vinegar and; in the last case, the saline solution and the sea water.
- Solids: The solute can be a gas, a liquid or a solid and the solvent a solid. When the solute is a liquid and the solvent a solid, the most common is dental amalgam (silver mercury). And when both the solvent and the solvent are solid, there are alloys such as bronze (tin in copper) and steel (carbon in iron).
General properties of aqueous solutions.
Electrolytic properties
all solutes that dissolve in water are grouped into two categories:
- Electrolytes is a substance that, when dissolved in water, forms a solution that conducts electricity.
- Non-electrolyte: does not conduct electric current when dissolved in water
These can be classified as:
-Strong electrolytes: the solute dissociates 100% in sussions. -Weak electrolytes: the solute does not dissociate 100% in its ions.
Characteristics of solutions
1-, They are homogeneous mixtures, that is to say, that the substances that make it up occupy a single phase, and they present a regular distribution of their physical and chemical properties, therefore when dividing the solution into n equal or different parts, each one portion will yield the same physical and chemical properties.
2-, The amount of solute and the amount of solvent are in proportions that vary between certain limits. For example, 100 g of water at 0 ºC is capable of dissolving up to 37.5 g of NaCl, but if we mix 40 g of NaCl with 100 g of water at the indicated temperature, there will be an excess of undissolved solute.
3-, Its physical properties depend on its concentration.
Eg dissol. HCl 12 mol / L Density = 1.18 g / cm3 dissol. HCl 6 mol / L Density = 1.10 g / cm3
4-, Its components are separated by phase changes, such as melting, evaporation, condensation, etc.
Ex: To separate the components of an aqueous NaCl solution, it is carried out by evaporation, that is, the solution is subjected to heating, when the boiling temperature of the solvent is reached, it is separated as a gas, leaving the salt as residue.
5-, They have no sedimentation, that is, when submitting a solution to a centrifugation process, the solute particles do not settle because their size is less than 10 Angstrom (ºA).
