What is a Mole?

In the field of chemistry, a mole is defined as the amount of a substance that contains exactly 6.02214076 * 10²³ ‘elementary entities’ of the given substance.

The number 6.02214076*10²³ is popularly known as the Avogadro constant and is often denoted by the symbol ‘N_A’. The elementary entities that can be represented in moles can be atoms, molecules, monoatomic/polyatomic ions, and other particles (such as electrons).

For example, one mole of a pure carbon-12 (¹²C) sample will have a mass of exactly 12 grams and will contain 6.02214076*10²³ (N_A) number of ¹²C atoms. The number of moles of a substance in a given pure sample can be represented by the following formula:

n = N/N_A

Where n is the number of moles of the substance (or elementary entity), N is the total number of elementary entities in the sample, and N_A is the Avogadro constant.

The word “mole” was introduced around the year 1896 by the German chemist Wilhelm Ostwald, who derived the term from the Latin word moles meaning a ‘heap’ or ‘pile.

The number of moles of a molecule may not always be equal to the number of moles of its constituent elements. For example, a mole of water contains NA number of H2O molecules. However, each water molecule contains 2 hydrogen atoms and one oxygen atom. Therefore, one mole of H2O contains 2 moles of hydrogen and one mole of oxygen.

How many grams of oxygen is required to burn completely 570 grams of octane. In this video you will get solution to this question.