Mole: The mass of substance containing the same number of fundamental units as there are atoms in exactly 12.000 g of 12C. Mole is the unit representing the amount of atoms, ions, or molecules.
- One Mole is the amount of a substance that contains 6 x 1023 particles (Atoms, Molecules or Formulae) of the substance (6 x 1023 is known as the Avogadro Number).
1 mole of Sodium (Na) contains 6 x 1023 Atoms of Sodium
1 mole of Hydrogen (H2) contains 6 x 1023 Molecules of Hydrogen
1 mole of Sodium Chloride (NaCl) contains 6 x 1023 Formulae of Sodium Chloride
Amount in Moles = Mass of Substance in grams ÷ Mr (or Ar)
Mass of Substance (grams) = Moles x Mr
CALCULATING RELATIVE FORMULA MASS
Mr = Mass of Substance in Grams ÷ Moles
10 moles of Carbon Dioxide has a Mass of 440 g. What is the Relative Formula Mass of Carbon Dioxide?
Relative Formula Mass = Mass ÷ Number of Moles
Relative Formula Mass = 440 ÷ 10 = 44
Relative Formula Mass of Carbon Dioxide = 44