• Knowing the number of moles allows you to calculate the number of atoms if you are dealing with chemical compounds.
• Moles are very useful, they allow chemists to use chemical equations to determine the mass of reactants and products.

Read about Avogadro Constant

Example

How many moles in 1000 g of C₁₂H₂₂O₁₁ (sugar)?

Solution:

Step 1: Molar mass = 12(12.01) + 22(1.008) + 11(16) = 342.296g/mol

Step 2: n = m/mm = 1000g/342.296g per mol = 2.92 moles (rounded)

Atomic mass from the periodic table

Elements	Symbol	Atomic Mass
Hydrogen	H	1.00794
Carbon	C	12.0107
Oxygen	O	15.9994