Concept Of Mole

CHAPTER 3 : CHEMICAL FORMULAE & EQUATIONS 3.2 The Mole & the Number of Particles

3.2 The Mole & the Number of Particles By the end of this lesson you should be able to:

1.Define a mole 2.State the meaning of Avogadro constant, NA 3.Relate the number of particles in one mole of substance using the NA 4.Solve numerical problems to convert the number of moles of particles of a given substances and vice versa

THE MEANING OF MOLE

AVOGADRO CONSTANT

Relationship

Solve Problems

How do chemist measure the amount of substances? a MOLE An amount of substance that contains as many particles as the number of atoms in exactly 12 g of C-12

The symbol of mole is mol

How many atoms in 12g of C-12?

The value is 6.02 x 10

23

AVOGADRO CONSTANT, NA -Defined as the number of particles in one mole of a substance

AVOGADRO CONSTANT, NA -1 mole of substance contains 6.02 x 1023 particles

•1 mole of atomic substance = 6.02 x 1023 atoms •1 mole of molecular substances = 6.02 x 1023 molecules •1 mole of ionic substances = 6.02 x 1023 formula units

Relationship between the number of moles and the number of particles x NA No. of Moles

No. of Particles NA

Simplest way to remember:

PAMONA