Veiligheid
Orde en netheid
Werk
Gedrag
Labcoat on and closed?
Glassware cleaned?
Use of material?
Safety of fellow students?
Hair in order?
Book bag?
Table and sink cleaned?
Execution?
Smooth collaboration?
Attention to P- and H-sentences?
Everything back in the right place?
Conclusion?
Talking to other groups?
Safety glasses?
Waste sorted?
Reflection?
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.
Determine the concentration of sodium hydroxide by titration with a calibrated HCl solution of 0.10 mol/L. The NaOH solution is provided.
Principle of titration and of acid-base indicators.
Materiaal (Materials): 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-sentences
Pipette 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. Rinse by letting a full burette of tap water drain through.
Proefopstelling (Experimental setup): (make a drawing and name the parts)
Beginstand buret (mL) = Initial burette reading (mL)
Eindstand buret (mL) = Final burette reading (mL)
Toegevoegd volume 0,10 mol/L HCl (mL) = Added volume of 0.10 mol/L HCl (mL)
Titratie 1
Titratie 2
Titratie 3
Gemiddeld toegevoegd volume (mL) = Average added volume (mL)
Calculate the concentration of NaOH in the solution, expressed in mol/L.
Calculate the concentration of NaOH in the solution, expressed in m/V%.
Does the calculated concentration correspond to the value stated on the label? If not, what could be the reason for this?
Titration of NaOH with HCl