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NaOH Concentration Determination by Titration

Onderzoekspracticum: Bepaling van NaOH-concentratie mbv titratie

Attitudes

  • Veiligheid:
    • Lab coat on and closed?
    • Safety of fellow students?
    • Safety glasses?
  • Order and cleanliness:
    • Glassware cleaned?
    • Hair in order?
    • Textbook?
    • Table and sink cleaned?
    • Waste sorted?
  • Work:
    • Use of material?
    • Attention to P- and H-phrases?
    • Everything back in its place?
  • Behavior:
    • Smooth collaboration?
    • Talking to other groups?
  • Conclusion:
    • Reflection?

DOEL VAN HET PRACTICUM (Goal of the Practicum)

  • Determination of the concentration of sodium hydroxide by titration with a calibrated HCl solution of 0.10 mol/L.
  • Learning to handle volumetric material: volumetric flask, pipette, pipette pump, burette.

Oriënteren (Orientation)

  • Onderzoeksvraag (Research question): Determine the concentration of sodium hydroxide by titration with a calibrated HCl solution of 0.10 mol/L. The NaOH solution is provided.
  • Onderzoeksprobleem (Research problem): Same as research question.

Voorbereiden (Preparation)

A - Informatie verzamelen = vooronderzoek (Gathering information = preliminary research)

  • Principle of titration and of acid-base indicators.

B Benodigdheden (Requirements)

  • Materiaal (Material): burette, stand, burette clamp, 250 mL Erlenmeyer flask, 100 mL graduated cylinder, 10 mL pipette, funnel, white card as background.
  • Stoffen (Substances):
    • Phenolphthalein, distilled water
    • NaOH solution H 315-319 P 280.1+3-305+351+338
    • HCl solution 0.10 mol/L – no H- and P-phrases

Uitvoeren (Execution)

Werkwijze (Method)

  • Using a pipette, transfer exactly 10 mL of the NaOH solution into an Erlenmeyer flask, add a few drops of phenolphthalein, and homogenize.
  • Fill the burette with the 0.10 mol/L HCl solution.
  • Record the initial reading of the HCl solution in the burette.
  • Titrate until colorless.
  • Record the final reading of the HCl solution in the burette.
  • Perform the titration at least three times and calculate the average added volume.
  • Let the burette drain completely. Rinse by letting a full burette of tap water drain through.
  • Proefopstelling (maak een tekening en benoem de onderdelen) - Experimental setup (make a drawing and name the parts)

Meetgegevens (Measurements)

Titratie 1Titratie 2Titratie 3Gemiddeld toegevoegd volume (mL) (Average added volume (mL))
Beginstand buret (mL) (Initial burette reading (mL))
Eindstand buret (mL) (Final burette reading (mL))
Toegevoegd volume 0,10 mol/L HCl (mL) (Added volume 0.10 mol/L HCl (mL))

Berekeningen (Calculations)

  • Calculate the concentration of NaOH in the solution, expressed in mol/L.
  • Calculate the concentration of NaOH in the solution, expressed in m/V%.

Rapporteren - Reflecteren (Reporting - Reflection)

  • Evalueren uitvoering - Evaluating execution
  • Does the calculated concentration correspond to the value stated on the label? If not, what could be the reasons for this?