titration

• method for a tritration?

  1. wash equipment
  2. pipette 25cm3 of alkali into a conical flask
  3. touch the surface of the alkali to ensure the correct amount is added
  4. fill jet space of the burette with the acid
  5. add an indicator
  6. put conical flask ontop of a white tile
  7. add acid drip by drip while swirling the flask
  8. record burette reading before and after
  9. repeat titration until you get atleast 2 concordant results
• what do we rinse equpments with?

  burette - acid

  pipette - alkali

  conical flask - distilled water
• why do we rinse the conical flask with water?

  to ensure all the acid is reacting with the alkali , since the water doesnt react with the reactants it wont affect moles so wont effect titration reading
• what is phenolphthalein ?


  • a universal indicator
  • used is NaOH is used
  • pink - alkali
  • colourless- acid
• what is methyl orange?

  • universal indicator
  • used if HCl is used
  • yellow - alkali
  • red - acid
  • endpoint orange
• what happens if the jet space isnt filled properly?

  If the jet space is not filled properly prior to commencing the titration it will lead to errors if it then fills during the titration, leading to a larger than expected titre reading
• why do we use a conical flask?

  A conical flask is used in preference to a beaker because it is easier to swirl the mixture in a conical flask without spilling the contents
• what happens if too much indicator is added?

  Indicators are generally weak acids so only add a few drops of them. If too much is added it will affect the titration result.
• concordant results


  lf 2 or 3 values are within 0.10cm3 and therefore concordant or close then we can say results are accurate and repeatable and the titration technique is good/ consistent