What is mol?

We explain to you what the mole is, one of the fundamental physical magnitudes contemplated by the International System of Units.

1. What is mol?

The mole is one of the magnitudes stipulated by the International System of Units . Its symbol is “mol”. The mole is defined as the amount of matter that particles possess , that is, atoms and elementary entities.

The mass of one mole of substance, called a molar mass, is equivalent to the atomic or molecular mass (depending on whether a mole of atoms or molecules has been considered ) expressed in grams.

The Avogadro number is the number of particles, whether these molecules, atoms, electrons , etc. that exist in one mole of any substance. It is a unit of elementary measurement in chemistry as it allows to know the value or quantity of very small particles. Being of such small sizes the value in which it will be expressed is usually very large or high.

2. How is mol calculated?

Avogadro’s number responds to a constant , that is, it is always the same, this corresponds to the value 6.023 × 10 ^ 23 mol (-1). This number of atomic mass units is equal to one gram of mass. In other words 6.023 × 10 ^ 23 uma (measurement of atomic mass) is equal to one gram. The atom-gram ratio is equal to one mole, which is in turn equivalent to the atomic mass, but if it is expressed in the unit of grams.

To calculate the moles it is necessary to know the atomic or molecular mass , depending on whether they are atoms or compounds respectively. From there the conversion will take place, just as if an exchange of units were made. Then to calculate the number of moles of molecules or atoms, the fraction between the mass of the substance, on the molecular or atomic mass must be made.

In synthesis , 1 mole of a substance is equivalent to 6.02214129 (30) × 10 ²³  elementary units.

3. Volume of one mole

When the substances are in a gaseous state it is possible to calculate the volume occupied by one mole. The volume refers to the magnitude in which the extension of a body (width, length and height) is expressed. Its unit is the cubic meter .

Under the so-called normal conditions of temperature and pressure , the volume of one mole of gas equals 22.4 liters . This means that under the same conditions of temperature and pressure, two moles of different gases will occupy exactly the same volume .