# Number Of Moles Formula

## Number of Moles Formula

A mole of a defined substance is defined as the mass of that substance containing the same number of fundamental units just like atoms in 12.0 g of 12C. These fundamental units can be atoms, molecules, or formula units based on the substance. It represents the number of chemical elements. One mole of any substance is equal to the Avogadro number whose value is 6.023 x 1023. It can be used to measure the products in a chemical reaction. The unit is defined denoted by mol.

The number of moles formula is given by

$Number\;&space;of\;&space;Moles=\frac{Mass\;&space;of\;&space;substance}{Mass\;&space;of\;&space;one\;&space;mole}$

Example 1

Determine the number of moles in 0.325g of barium hydroxide.

Solution:

Given values are,

Mass of Ba(OH)2 = 0.325g

Mass of one mole of Ba(OH)2 = 171g

Number of moles formula is expressed by,

Number of moles = Mass of substance / Mass of one mole

= 0.325 / 171

= 0.00190 mol

Example 2

Determine the number of moles in 95g of MnO2.

Solution:

Given values are,

Mass of MnO2 = 95g

Mass of one mole MnO2 = 86.94g

Number of moles formula is given by,

Number of moles = Mass of substance / Mass of one mole

= 95 / 86.94

= 1.092 mol