avogadro constant

Chemistry Chemistry

Formulae & Formulae &

EquationsEquations

Mole Concept Avogadro Number, NA

Group 17

a) 1 dozen = 12 units b) 1 pair = 2 units

Daily life – we used:

To delegate a big quantity:

Definition

Chemistry- mole concept:

Mole is a substance quantity that contain a

number of particles such as atom, ion, or

molecule that have equal number of atom in 12

gram of 12C or 6.02 x 1023 particles

Example:

1 mole carbon atoms = 6.02 x 1023 carbon atoms

1 year = 12 months

1 kg = 1000 g

1 month = 30 days

1 km = 1000 m

1 dozen oxygen atoms = 12 oxygen atoms

1 mole oxygen atoms = 6.02 x 1023 oxygen atoms

1 mole sodium atoms = 6.02 x 1023 sodium atoms

Daily life

Chemistry

Avogadro’s Number/ Avogadro's Constant, NA

1 Mole of Substance = 6.02 x 1023 Particles

NA = 6.02 x 1023 mol-1

examples

Analogy:

Large Constant

1 mole = 6.02 x 1023 representative particles of a substance

Substance

NA = 6.02 x 10 23 mole-1 Particles

Amedeo Amedeo AvogadroAvogadro

Avogadro's number has been experimentally determined to

be 6.02 x 1023 molecules gram mole-1

Avogadro's number, NA= 6.02 x 1023 particles theorized by

Amadeo Avogadro later mathematically proven by Sanislao

Canizzaro around the 1750's.

NA

Example 1:

Sodium, Na NaOH Water, H2O

RAM/ RMM (g/mole)

Mole

Particles

23.0 23+16+1 = 40

(2x1) + 16 = 18

11 1

6.02x1023mole-1molecules/

3 (6.02x1023 mole-1 atoms)

6.02 x 1023

mole-1molecules

6.02 x 1023

mole-1 atoms

Helium (He) Hydrogen (H)

• 1(4 g/mole) = 4 g/mole• 1 mole• 6.02 x 1023 particles

• 4 (1 g/mole) = 4 g/mole• 4 mole• 4 (6.02 x 1023 particles)

Example 2:

 1. Define the definition of  Mole concept:

Mole is a quantity that contain a number of particles such as atom, ion, or molecule that have equal number of atom in 12 gram of 12C or 6.02 x 1023 particles.

NA = 6.02 x 1023 mol-1

Avogadro Number:

Question

2. If 1 mole of a substance contains 6.02 x 1023 particles, than,

1 mole of Na contains

1 mole of Na+ contains

1 mole of H2O contains 6.02 x 1023 water molecules

6.02 x 1023 sodium ions

6.02 x 1023 sodium atoms

3. Calculate number of mole and a atomic number of each substance given below and fill in the table with the correct answers. 

Substance Number of Mole Atomic Number

Iron 1.0 6.02 X1023

Potassium 2.0

Carbon 0.5 X 6.02 x 1023

Helium

Aluminium 0.2

2.0 X 6.02 x1023

0.5

1.5 1.5 X 6.02 x 1023

0.2 X 6.02 x 1023

 1. Define the definition of  Mole concept:

Mole is a quantity that contain a number of particles such as atom, ion, or molecule that have equal number of atom in 12 gram of 12C or 6.02 x 1023 particles.

NA = 6.02 x 1023 mol-1

Avogadro Number:

Quiz

2. Calculate number of mole, molecule number and atomic number of each substance given below and fill in the table with the correct answers.

Molecule compound

Number of Mole

Compound

Molecule Number

Atomic Number

Water, H2O 1 6.02 x 1023 2 X 6.02 x 1023 atom hydrogen 6.02 x 1023 atom oxygen

Carbon dioxide, CO2

1 6.02 x 1023 6.02 x 1023 atom carbon 2 X 6.02 x 1023 atom oxygenAmmonia,

NH3

0.5 0.5x6.02x1023 0.5 X 6.02 x 1023 atom nitrogen3 X 0.5 x 6.02 x 1023 atom hydrogen

Hydrogen chloride, HCl

3 3 x 6.02 x 1023 3 X 6.02 x 1023 atom hydrogen 3 X 6.02 x 1023 atom chloride