Summary Quantitative Chemistry

QUANTITATIVE CHEMISTRY

COVEALENT CHEMICAL FORMULAE
 These compounds contain molecules
 Molecules are formed when non-metal atoms are covalently bonded
together
 All molecules are different
Diatomic molecules consist of two atoms that are covalently bonded together,
these two atoms can be from the same or different elements e.g. N 2 CO2



IONIC CHEMICAL FORMULAE
 Formed as a result of ionic bonding
 Ionic compounds contain cations (+) and anions (-)
There are two types of ionic formulae:
 simple ionic formulae = NaCl
 polyatomic ionic formulae = CaSO4



RELITIVE ATOMIC MASS
Relative formula mass is calculated by adding the relative atomic masses of
each of the atoms found in a chemical formula
a.m.u – atomic mass unit



THE MOLE
Mol – the amount of substance expressed in grams which contains as many
elementary particles as there are in 12g of the carbon – 12 isotope
o symbol = n
o unit = mol
Molar mass – the mass in grams of one mol of that substance