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)

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?