titration

• What is the general equation for neutralisation reactions?

  Acid + alkali -> salt + water
• What is the purpose of titration?

  To find unknown concentrations of acids and alkalis
• Why is an indicator used in a titration?

  To determine when the acid has neutralised the alkali by changing colour
• What is the importance of swirling the conical flask during titration?

  To ensure the acid is evenly distributed
• What are the steps involved in performing a titration?

  1. Use a pipette to add 25cm of alkali to a conical flask.
  2. Add drops of indicator and place on a white tile.
  3. Fill the burette with acid and note the starting volume.
  4. Slowly add acid to the alkali while swirling.
  5. Stop when the indicator changes colour.
  6. Note the final volume and calculate the volume of acid used.
  7. Repeat until concordant results (0.2cm difference or less).
  8. Calculate moles from concentration and volume, then find the concentration.
• What are the three different types of indicators used in titration?

  1. Litmus: red in acidic, blue in alkaline
  2. Phenolphthalein: no colour in acidic, pink in alkaline
  3. Methyl orange: red in acidic, yellow in alkaline
• What colour does litmus turn in an alkaline solution?

  Blue
• What colour does phenolphthalein turn in an alkaline solution?

  Pink
• What colour does methyl orange turn in an alkaline solution?

  Yellow
• What is the colour of methyl orange in an acidic solution?

  Red
• What is the colour of phenolphthalein in an acidic solution?

  No colour
• How do the colours of indicators change in response to pH levels?

  They change colour when the pH transitions from acidic to alkaline
• What is the colour of litmus in an acidic solution?

  Red