quantitative analysis

• acid-alkali titration practical:

  The burette is washed with acid and the pipette with alkali

  • _cm3 of alkali is measured with a pipette

  • Add alkali to the conical flask

  • An indicator (phenol pthalein)is added to conical flask

  • A white tile is placed under the flask

  • The burette is filled with acid and a starting measurement of volume is taken

  • Acid is dropped into the flask until the end point is reached

  • At the end point the indicator abruptly changes colour

  • A second burette measurement is taken at end point

  • The experiment is repeated until results are concordant
• mole (mol) = mass (g)/ relative mass
• concentration (g/dm^3) = mass (g)/volume (dm^3)
• mol dm^-3 x Mr -> g dm^-3 is

  g dm^-3 divide by Mr -> mol dm^-3
• percentage yield = actual yield/ theoretical field x 100
• actual yield is usually less than theoretical yield because:

  • incomplete reactions
  • practical losses during the experiment
  • competing side reactions
• the molar volume, of any gas at room temperature and pressure, is the volume occupied by one mole of molecules of any gas at room temperature and pressure

  it is usually 24dm^3
• moles = volume (dm^3)/molar volume (24)