Practical 1a + 1b

• Why must the funnel not be in the top of the burrette when the titration is being carried out?

  To ensure a drop of solution doesn't drop into the burette and affect the titre
• Concordant results is when titres are within 0.10cm3 of each other
• Why is the inside of the conical flask rinsed down with distilled water and the flask swirled close to the endpoint?

  To ensure any solution on the sides of flask are washed into the man solution
• Why does adding water, or rinsing the conical flask with distilled water, not affect the titre?

  It doesn't affect the mol of acid and alkali in the conical flask
• Why do you add the solution from burette drowse and with swirling close to the endpoint?

  One drop will cause a sharp change in pH which cause a sudden change in the indicator
• Practical 1a - Making a standard solution

  1. Weigh out Xg of solid in a weighing boat. Record mass of solid and weighing boat.
  2. Transfer solid into a beaker and add 100cm^3 of distilled water. Stir with glass rod until all the solid has dissolved.
  3. Re-weigh empty weighing boat and record accurate mass of solid used (weighing by difference)
  4. Transfer the solution into a volumetric flask using a funnel
  5. Transfer all washings- rinse beaker, glass rod and funnel w/ distilled water
  6. Make up to 250cm^3 of solution by adding distilled water
  7. Invert volumetric flask thoroughly
• Practical 1b

  1. Clean all the equipment with distilled water
  2. Rinse the burette with acid to prevent dilution
  3. Fill the burette with acid and record the initial volume
  4. Transfer 25cm³ of alkali using a pipette into a conical flask
  5. Add a few drops of indicator (weak organic acid)
  6. Open the tap and while swirling allow the acid to react with the alkali
  7. Add the acid dropwise close to the endpoint
  8. Stop adding acid when the colour of the indicator changes and record the final volume
  9. Repeat to get concordant values (within 0.10 cm³ of each other)