Calculating moles in an element

• Mole


  A very large number that represents the number of particles (atoms, molecules, ions) in one mole of a substance
• The mole is a shorthand way of saying the number of particles in one mole of a substance
• Relative atomic mass

  The mass of a single atom of an element, calculated from the average masses of the isotopes weighted for their abundance
• Relative atomic masses are found on the periodic table and given in exams
• Calculating number of moles

  Mass of element (g) / Relative atomic mass = Number of moles
• Calculating number of moles

  • 48 g of Mg / 24 = 2 moles of Mg
  • 120 g of Ca / 40 = 3 moles of Ca
  • 252.2 g of Fe / 56 = 4.5 moles of Fe
  • 4,064 g of S / 32 = 127 moles of S