# Solution and solubility

Homogeneous mixtures are also called solutions. The components (substances present) of a solution may be in the states: solid, liquid or gaseous. We can say that the solution is a type of matter formed by a solvent and a solute.

Solute is the substance that is dissolved in the solvent. Solvent is the substance that dissolves the solute. For example, brine is a type of matter composed of a solution formed by salt and water. Salt is the solute, as it is dissolved in water, and water is the solvent, since it dissolves salt.

There are also gas mixtures, called gas mixtures. Regardless of the proportion of each of its components, the gas mixture is a solution, that is, a homogeneous mixture. This explains, for example, why we cannot see water vapor mixed with other atmospheric gases.

Other homogeneous mixtures or solutions are atmospheric air, gasoline etc.

Depending on the amount of solute relative to solvent, the solution can be:

• diluted - small amount of solute
• concentrated - large amount of solute
• saturated - Solute in maximum quantity that the solvent can dissolve.

The solubility coefficient of a substance indicates the maximum amount of a solute that can be dissolved in a given solvent. This value varies with temperature.

There are several ways to indicate the amount of solute present in a solution. One of the most used is the common concentration, calculated using the equation:

on what: Ç it is the concentration;

m is the mass of the solute expressed in grams;

V is the volume of the solution expressed in liters.

The salt concentration in seawater averages 30 g / l, ie in each liter of seawater there is 30 grams of salt. In saline regions the concentration is higher than this average.