1. The Mole
Chapter 7-1

2. The Mole
The mole
The mole is a standard scientific unit for measuring large quantities of very small entities, such as atoms, molecules, or formula units.
A chemical mass unit.
A mole is similar to
1 pair = 2
1 dozen = 12
1 mole = x 1023

3. Avogadro’s Number
How Avogadro’s number is related to a mole of any substance?
The mole is the amount of substance that contains 6.02 x 1023 representative particles (atoms, molecules, formula units, etc.) of that substance.
6.02 x 1023 is also known as Avogadro’s number
The mole is used in chemical calculations
1 mole = 1 mol

4. Sample Problems How many moles are in 2.80 x 1024 atoms of Si?
1 mol Si
2.80 x 1024 atoms of Si x
6.02 x 1023 atoms of Si
= mol Si

5. How many molecules are in 3.06 moles of NO2?

6. How many atoms are in 5.03 moles of H2O?