Chemistry

03. Preparation of a soluble salt by titration

  • 00:44 Why does touching the wall of the flask with the tip of the pipette cause some of the liquid to leave? 
  • 00:58 Why does the indicator turn pink?
  • 01:31 Why is it important to remove the funnel?
  • 01:35 Why is it important to remove the air bubbles from the burette jet? 
  • 02:10 Why is it important to swirl the flask?
  • 02:25 Why is it important not to add more acid after the solution turns colourless? 
  • 02:40 Why is it important not to round-off measurements during calculations?
  • 02:50 Why is it important not to include the indicator this time?
  • 02:54 Why is it important to add exactly the same volume of acid the second time?
  • 03:10 Why is it important to heat gently?
  • 03:10 Why not evaporate all of the water?

  • 50 cm³ burette

  • funnel

  • 25 cm³ pipette and filler

  • 100 cm³ conical flasks

  • pyrex glass evaporating basin

  • 0.1 mol dm-³ NaOH solution

  • 0.1 mol dm-³ HCl solution

  • Phenolphthalein indicator

Hazard Risk Control measure

0.1 mol dm-3 NaOH solution

Contact with eyes and skin

Eye: flood with tap water (10 min) 
Skin: drench with water

0.1 mol dm-3 HCl solution

Contact with eyes

Eye: flood with tap water (10 min)

Phenolphthalein indicator

Acute toxicity, serious health hazard, corrosive, hazardous to the aquatic environment, flammable.

Avoid naked flames