Acid-alkali titration

• What is the aim of the acid-alkali titration experiment?

  To carry out an accurate titration
• What equipment is needed for the acid-alkali titration?

  • 50 cm​3​ burette
  • 25 cm​3​ pipette with pipette filler
  • 250 cm​3​ conical flask
  • 100 cm​3​ beaker
  • Funnel
  • White tile
  • Burette clamp and stand
• What chemicals are required for the titration?

  • Phenolphthalein indicator
  • 0.4 mol/dm​3 ​hydrochloric acid
  • Sodium hydroxide solution (unknown concentration)
  • Deionised water
• Why is phenolphthalein used in the titration?

  It indicates the endpoint by changing color
• How much sodium hydroxide should be added to the conical flask?

  25 cm​3​ using a pipette
• What is the purpose of placing the conical flask on a white tile?

  To make the color change easier to see
• Why must the conical flask be swirled during the titration?

  To ensure all reactants are mixed thoroughly
• What should be done after the rough trial titration?

  Record the final burette volume
• What is the significance of concordant titres?

  They ensure accurate and reliable results
• What is the equation for the reaction in the titration?

  HCl + NaOH → NaCl + H​2​O
• How should the volume of acid in the burette be read?

  At eye level from the bottom of the meniscus
• What color does phenolphthalein turn in alkalis?

  Pink
• What safety precautions should be taken during the experiment?

  Wear safety goggles and handle glassware carefully
• What steps are involved in determining the concentration of sodium hydroxide?

  1. Find moles of HCl used.
  2. Use the 1:1 ratio for NaOH.
  3. Divide moles of NaOH by volume used.
  4. Round to 3 significant figures.
• What should be done if sodium hydroxide contacts the skin?

  Wash immediately with water
• What should be done if hydrochloric acid spills?

  Handle with care and clean immediately
• Why is it important to record the initial burette reading?

  To calculate the volume of acid used
• How do you calculate the titre volume?

  Final burette reading minus initial reading
• What is the endpoint in a titration?

  The point where the indicator first changes color
• What is the purpose of rinsing the conical flask with deionised water?

  To remove any contaminants before titration
• What is the role of the funnel in the titration setup?

  To pour liquids into the burette safely
• Why must the rough titre not be used to calculate the mean?

  It is not accurate enough
• What is the volume of hydrochloric acid poured into the burette?

  About 10 cm​3​
• What is the purpose of the beaker in the experiment?

  To catch any excess acid from the burette
• What should be done after reaching the endpoint?

  Record the final burette reading
• What is the significance of using deionised water in the experiment?

  To avoid introducing impurities into the reaction
• How can the results from the titration be recorded?

  In a table with initial and final volumes
• What is the first step in the titration method?

  Add 25 cm​3​ of sodium hydroxide to the flask
• Why is it important to swirl the conical flask constantly during titration?

  To ensure thorough mixing of reactants
• What should be done if the initial burette reading is not clear?

  Adjust the lighting or reposition the burette
• What is the final step in the titration process?

  Calculate the mean titre from concordant results
• What is the purpose of using a white tile during the titration?

  To enhance visibility of the color change
• How does the concentration of sodium hydroxide relate to the volume of hydrochloric acid used?

  It is determined by the titration results
• What should be done if the solution in the conical flask turns pink?

  Add hydrochloric acid drop by drop
• What is the role of the burette in the titration process?

  To accurately dispense the acid solution
• Why is it important to repeat the titration multiple times?

  To ensure reliability and accuracy of results
• What is the purpose of the funnel in the titration setup?

  To pour liquids into the burette safely
• What should be done if the sodium hydroxide solution is spilled?

  Clean it up immediately and safely
• How can the accuracy of the titration be improved?

  By using more precise measuring equipment
• What is the significance of the mean titre in titration?

  It provides an average volume used