Mole in Chemistry

In Science, the concept of a mole is usually used to measure the number of particles. Such as a molecule like Helium has an atomic weight of an atom is 4.002602 and replacing with a complex molecule like sucrose (C₁₂H₂₂O₁₁) has an atomic weight of 342.30 so here the value of a single mole is 342.30.

As per routine, the mole is used by scientists when it’s a matter of a large number of particles like atoms, molecules, and electrons. It is the unit of measurement in the International System of Units (SI) for the amount of Substance and is represented by mol.

The mol is expressed by the Avogadro constant having a value of 6.02 10²³ mol^-1. Further in this article, we will define moles with examples, detail, and their historical use needs and methods to find the number of moles in this article.

Definition of mole:

A useful concept in chemistry is the idea of a mole. In mole, we count collections of fixed chemical objects such as atoms or molecules.

For Instance:

Number of Electrons in a Mole of Hydrogen Molecule.

The number of electrons in a mole of the hydrogen molecule is 1 mole of H₂ contains 6.023×10²³ molecules and each molecule of H₂ contains two electrons.

1 mole = 6.023 × 10²³

Therefore no. of electrons in one mole of (Hydrogen) H₂ = 2 * 6.023 × 10²³

Total number of electrons = 12.046 × 10²³

Formula of mole:

The formula for calculating the mol of a substance is given below:

Number of Moles = Mass of the Sample / Molar Mass

To find the number of moles, we must have the mass of the sample and the molar mass then by using the above formula we can calculate it. Similarly, we can find the mass of the sample or its molar mass using the above formula if the other two quantities are given.

Relation between the number of atoms and mol:

The number of atoms or molecules in a problem can be found by multiplying the number of moles with the Avogadro constant. This formula can be written as:

Number of Atoms = Number of Moles * 6.022*10²³

Why do we use moles?

Units are invented when available units are not fitting everywhere then to tackle the situation of chemical reactions at some places grams can’t fill the gap between very small to very large numbers.

Examples of mole:

Methods of calculating the mol of a substance are also easy way given below in the example section, we have described the step-by-step solution.

Example 1:

Find the number of moles in 50 grams of O₂.

Solution:

Step 1: Write the given data

Mass of Oxygen = 50

Molecular mass of Oxygen = 2 * 16 = 32

∴ as the molecule of O₂ contains two atoms.

Step 2: Insert all values in the formula

Mole = mass / molecular weight

Mole = 50 / 32 = 1.5625 mol

50 grams of Oxygen has 1.5625 moles.

We can also convert the mole into grams.

Mole to grams:

In Science, we convert the mole of a substance into grams. Initially, we will manage equations, we need a mole ratio among reactants and reagents. The basic need for conversion is to practice the periodic table and it’s how to know from top to bottom.

A mole calculator is a helpful tool for the conversion of mole, mass, and molecular mass.

Example 2:

Convert 0.6 moles of KCl into grams.

Solution:

Step 1: Look up the periodic table and find the atomic masses of Potassium and Chlorine. The atomic mass is the gram per mole of an atom.

The atomic mass of potassium (K) = 39.09

The atomic mass of Chlorine (Cl) = 35

Step 2: Atomic mass or number of grams per mole of Potassium chloride can be obtained by adding up both masses.

Grams per mole of Potassium Chloride (KCl) = 39.09 + 35

Grams per mole of Potassium Chloride (KCl) = 74.09 g mol^-1

Step 3: Multiply the grams per mole by 0.6 to get the required answer.

Total grams in 0.6 moles of Potassium Chloride (KCl) = 0.6 g * 74.09 g mol^-1

Total grams in 0.6 moles of Potassium Chloride (KCl) = 44.45 g

Hence, 0.6 moles of Potassium Chloride (KCl) is 44.45 g.

Example 3:

Convert 0.8 moles of HCl into grams.

Solution:

Step 1: Look up the periodic table and find the atomic masses of Hydrogen and chlorine. The atomic mass is the gram per mole of an atom.

The atomic mass of Hydrogen = 1.008

The atomic mass of Chlorine = 35.0

But in the case of Hydrogen Chloride, there are one atom of Hydrogen and 1 atom of chlorine.

Step 2: Atomic mass or number of grams per mole of Hydrogen Chloride can be obtained by adding up both masses.

Grams per mole of Hydrogen Chloride (HCl) = 1.008 + 35.00

Grams per mole of Hydrogen Chloride (HCl) = 36.008 g mol^-1

Step 3: Multiply the grams per mole by 0.8 to get the required answer.

Total grams in 0.5 moles of Hydrogen Chloride (HCl) = 0.8 g * 36.008 g mol^-1

Total grams in 0.5 moles of Hydrogen Chloride (HCl) = 28.8064 g

Hence, 0.8 moles of Hydrogen Chloride (HCl) is 28.8064 g.

Summary:

In this article, detail on Mole is given to try to provide important points and maximum knowledge about mole after reading and completely understanding come to know that it is an effective way to find solutions and can easily defend mole.

Find the value of the number of moles after using it in research work if it is not enough then a new unit can be introduced easily which is more powerful than this and which can solve more problems and meet the early need of raising problems in the molecule.