What is the relationship between 1 mole and Avogadro's number? Let's start by defining what mol is:
The mole is the amount of matter in a system that contains as many elementary entities as there are atoms contained in 0.012 kilograms of carbon 12.
But what is carbon 12? 12C is the isotope of the element carbon with 6 protons, 6 neutrons and 6 electrons, it has a very important role in Chemistry. Carbon 12 was chosen as the reference standard for measuring atomic masses because it is the most abundant of all isotopes of the element carbon, occurs in nature in the relative percentage of 98,94%. Other isotopes of carbon such as 13C and 14C are found in smaller quantities.
Let's go back to the initial question: the relationship between mol and Avogadro's number. The number of elementary entities contained in 1 mol corresponds to Avogadro's constant, whose value is 6.02 x 1023 mol-1. This comparison was stipulated because 1 mole coincides with Avogadro's number.
Thus, it was defined that 1 mole of atoms is equal to 6.02 x 1023, and 1 mol contains 12 grams (equivalent to 12Ç).
1 mol = 6.02 x 1023 = 12 grams
Studying this content, a question may arise: where does Avogadro's number come from?
It comes from the studies of Amedeo Avogadro (1786-1856), this scientist was studying gases when he made a hypothesis, his researches were later recognized and the Avogadro constant appeared, in his honor.
Now an example of calculating the number of atoms based on Avogadro's constant:
How to calculate the number of atoms in 50 grams of Sodium (Na)?
Atomic mass of sodium = 23 g (grams)
Establishing a relationship with Avogadro's number we have:
1 mole of Na = 23 g = 6.02 x 1023
By the rule of three we will have:
In 23 g (Na) you have 6.02 x 1023 atoms
So in 50 g we have X atoms
Calculating:
23 — 6.02 x 1023
50 — X
X = 50 • 6.02 x 1023
23
X = 13.08 x 1023 atoms of Sodium (Na)
By Líria Alves
Graduated in Chemistry
Source: Brazil School - https://brasilescola.uol.com.br/quimica/mol-numero-avogadro-qual-relacao.htm
