Amount Of Substance (AS)

• Amount of Substance can be measured using the unit of a mole.
• One mole contains 6.02 x 10^23 particles (avogadros constant)
• Number of particles = number of moles * avogadro's constant
• number of moles = mass of substance / Mr
• number of moles = concentration * volume
• Ideal Gas Equation

  pV=nRT
• Temperature must be in Kelvin for the ideal gas equation and volume must be in metres cubed.
• Balanced equations have the same number of each atom on both sides.
• In an ionic equation, only the reacting particles and the products they form are included.
• State symbols must be placed after a reactant or product when writing down an equation.
• Titrations are used to find out the concentration of acid or alkali solutions.
• A standard solution has a known concentration.
• You complete a rough titration before completing an accurate titration.
• methyl orange

  red in acid

  yellow in alkali
• phenolphthalein

  colourless in acid

  pink in alkali
• Empirical formula gives the simplest whole number ratio of atoms of each element in a compound.
• Molecular formula gives the actual numbers of atoms of each element in a compound.
• Percentage yield is never 100%
• Theoretical yield is the mass of product that should be formed in a chemical reaction.
• The actual yield of a product will always be less than the thoretical yield.
• Percentage yield = (actual yield / theoretical yield)*100
• Atom economy is a measure of the efficiency of a reaction.
• % atom economy = (molecular mass of desired product / sum of molecular masses of all reactants)*100