topic c3- quantitive chemistry

• relative formula mass (Mr)

  the sum of atomic masses (Ar) of all atoms in a molecular formula
• how to calculate Mr- example

  
• moles

  amount of a substance that contains 6.02 x 10^23 particles
• 6.02 x 10^23 particles is know as

  avagadro's constant
• the mole

  mole is used as it relates actual mass (g- in gram) with atomic mass
• the mole- example

  carbon has an atomic mass of 12, so one mole of carbon weighs 12g
• the mole equation

  
• number of moles=

  mass (in grams) of element/ compound ///// Mr (relative/atomic mass) of element/ compound
• use the triangle to rearrange the

  mole equation
• mass

  Mr x mole
• mole

  mass / Mr
• Mr

  mass / mole
• mass

  is always conserved in a reaction
• concentration (g/dm^3) =

  mass of solute (g) / volume of solvent (dm^3)
• concentration

  the amount of a substance in a volume of a solution
• limiting reactants

  • the amount of product produced depends on the limiting reactant
  • the limiting reactant is the reactant (input) that will run out 1st in the reaction
• example of relative formula mass (Mr)

  
• balancing equations- example