VALUED SOLUTIONS: TYPES AND EXAMPLES - CHEMISTRY - 2025

Titrated solutions or standard solutions are those in which the concentration measurements of their components are known and followed accurately. Concentration measurements are standardized.

All substances are homogeneous mixtures composed of two basic elements: a solute and a solvent. The solute is the part that dissolves and the solvent is the part that dissolves the solute.

It should be noted that the solute is found in less quantity than the solvent. In this sense, in the titrated substances, the exact amounts of solute and solvent that are required to make the standard solution are known.

To make a titrated solution, each of the components of the solution must be weighed or measured and make sure that not a milligram of solute or solvent is adhered to any of the measuring instruments.

Empirical solutions and valued solutions

The solutions can be of two types: empirical or valued. The first are those in which the amounts of solute and solvent that are mixed are unknown. In empirical solutions, measurements don't matter.

In contrast, titrated solutions are those in which the amounts of solute and solvent that are mixed are known to the maker of the solution.

In this type of solutions, the measurements of the components are essential to guarantee the functioning of the substance.

Components of a valued solution

Generally speaking, the components of a valued solution are the same as those of any other solution. That is, a solute and a solvent.

The solute is the part of the solution that dissolves. It comes in less quantity. For its part, the solvent is the part of the solution that dissolves and is found in greater quantity.

Concentration

It is known as concentration as it expresses the relationship between the amounts of the elements in a solution (solute and solvent). This relationship is the one presented below:

Concentration = amount of solute / amount of solvent.

- Ways to present the concentration

Molarity

Generally, the concentrations of the standard solutions are expressed in units of moles per liter (mol / L), moles per cubic decimeter (mol / dm ³), kilomoles per cubic meter (kmol / m ³), among others. This measure of concentration is known as molarity.

The formula for molarity is as follows:

Molarity = number of moles of solute (mol) / liters of solution (L).

The unit of expression mol / L can be summarized in the unit M.

Percentage by mass (% by mass)

Another common form is the percentage by mass (% by mass). This concentration expression relates the mass of the solute to one hundred mass units of the solution.

Mass is usually expressed in grams, however, other mass measurements can be used.

The formula for the percentage by mass is as follows:

% by mass = (mass of solute / mass of solution) x 100

Percentage by volume (% by volume)

The volume percentage expresses the relationship between the amount of solute in volume and one hundred volume units of the solution. The most used measures are the liter (L) and the cubic centimeter (cm ³).

The formula for the percentage by volume is as follows:

% by volume = (volume of solute / volume of solution) x 100

Grams per liter (g / L)

This concentration expression establishes a relationship between the mass of solute (expressed in grams) and the volume of the solution (expressed in liters).

It is used in educational practices, however, it is not common in the professional field.

The formula for this expression is as follows:

g / L = grams of solute / liters of solution

Types of solutions valued

There are three types of titrated solutions: ionic, elemental, and formulated.

Ionic titrated solutions

They are those in which the components of the solution (the solute and the solvent) form ionic bonds. This means that two or more bound ions are present.

Of these ions, one is positively charged (called a cation) and the other is negatively charged (called an anion).

This type of solution is used for the analysis of anions such as chloride (Cl -) and sulfate (SO4 ^2-). It is also used in the analysis of cations such as sodium (Na +) and potassium (K +).

Elementary valued solutions

These solutions are made up of elements in their pure state and are obtained from solutions of other compounds.

Formulated Value Solutions

These solutions are based on calculating the atomic weight and the number of elements present in the solution.

Examples of valued solutions

Many labs produce stock solutions. The formulas for these substances are widely known, so any competent laboratory in the area can reproduce the results.

Here are some of these:

References

1. Standard solutions. Retrieved on August 2, 2017, from en.wikipedia.org
2. Standard solutions. Retrieved on August 2, 2017, from study.com
3. Standard solution definition. Retrieved on August 2, 2017, from thoughtco.com
4. Guide to Preparation of Standard Solutions. Retrieved on August 2, 2017, from chemiasoft.com
5. IUPAC Gold Book - Standard Solution. Retrieved on August 2, 2017, from goldbook.iupac.org
6. Stock Standard Solutions. Retrieved on August 2, 2017, from chemiasoft.com
7. Making Standard Solutions. Retrieved on August 2, 2017, from creative-chemestry.org.