Titrations

• • Titrations are used to analyse the concentrations of solutions
  • Titrations are used to find out how much acid is needed to neutralise an alkali - vise versa
• 1. Using a pipette and pipette filler, add set volume of acid/alkali to conical flask - add two or three drops of indicator
• 2. Use funnel to fill burette with some acid/alkali of known concentration. Record the initial volume of the acid in burette
• 3. Using burette, add acid/alkali to acid/alkali slowly
• 4. The indicator changes colour when all alkali/acid has been neutralised
• 5. Record final volume of acid/alkali in burette, along with initial reading to calculate volume of acid/alkali used to neutralise acid/alkali
• • Universal indicators gradually change colour as it is a mixture of different indicators
  • During a titration, a sudden colour change is needed
  • Single indicators are needed to get this
• • litmus = red in acid, blue in alkali
  • phenolphthalein = colourless in acid, pink in alkali
  • methyl orange = red in acid, yellow in alkali