LESSON 7 THE MOLE CONCEPT

THE MOLE CONCEPT

References : Mohammed and Lambert ( Old Edition) Chapter 11 pg. 107 Mohammed and Lambert ( New edition) Chapter 8 pg 123 Anne Tindale Chapter 10 pg 46

The following topics will be covered :

1. Definition of Relative Atomic and Relative Molecular Masses.
2. Calculation of Relative Molecular Masses
3. Converting Moles to Grams / Grams to Moles
4. Calculation from equations
Masses of substances /Volumes of gases / Concentration of solutions (Practical :Volumetric Analysis )
5. % Composition
6. Empirical Formulae
7. Avagadro’s Number

THE MOLE DIAGRAM

VOLUME MASS
Multiply by 22.4 Multiply by RMM

# PARTICLES Multiply by 6.023 x 1023

RELATIVE ATOMIC MASS ( R.A.M.

of an element is the ratio of the mass of one atom of the element to one-twelfth the mass of a 12C atom. R.A.M. = mass of one atom of the element e.g. 27 amu = 27 (no units) mass of 1/12 of an atom of 12C 1 amu

R.A.M OF SOME COMMON ELEMENTS

SYMBOL

ELEMENT

R.A.M.

Al Aluminum
27
Ar Argon
40
Ba Barium
137
Be Beryllium
9
B Boron
11
Br Bromine
80
Ca Calcium
40
C