Moles and mass

• Formula that links moles, mass and Mr

  Mass= moles x Mr
• Mole

  A unit of measure.

  1 mole of a substance is the amount of that substance that contains 6.02x10*23 particles
• Avogadro’s constant

  The number of particles in 1 mole of a given substance. The value of the constant is 6.02x10*23
• Formula that links mass, Mr and moles

  Mass= moles x Mr
• Molar ratio

  The ratio between the moles of different reactants and products in a balanced equation
• Example of molar ratio

  N2 + 3H2 —> 2NH3

  Ratio of N2 : H2 : NH3 is 1 : 3 : 2