2022 IB Diploma Extended Essays

Raw data table 3: Volume of 0.1M NaOH used to neutralise the white wine in a back titration against HCl with Bromothymol indicator Trial Titration with NaOH Back titration with HCl Volume used to neutralise ( ± 0.4ml) Starting volume ( ± 0.1ml) Ending volume ( ± 0.1ml) Volume Used ( ± 0.2ml) Starting volume ( ± 0.1ml) Ending volume ( ± 0.1ml) Volume used ( ± 0.2ml)

1 2 3 4 5 6

17.0 32.0 0.00 15.1 30.8 0.10

32.0 46.4 15.1 30.8 46.4 14.5

15.0 14.4 15.1 15.7 15.6 14.4

25.0 28.0 30.0 32.6 35.8 38.9

28.0 30.0 32.6 35.8 38.9 40.9

3.00 2.00 2.60 3.20 3.10 2.00

12.0 12.4 12.5 12.5 12.5 12.4

Reasoning for error: To measure the volume of NaOH and HCl put into the wine, the burette with a 0.1ml uncertainty was used. As the burette was only read once for the starting volume and once for the ending volume, the uncertainty for each is 0.1ml. For the sample calculation of the volume used and the calculation for the uncertainty, refer to raw data table 1. Sample calculation for the volume used to neutralise: = − =15.0 ± 0.2 − 3.0 ± 0.2 =12.0 ± 0.4 Raw data table 4: Volume of 0.1M NaOH used to neutralise the white wine in a titration using a pH data logger Trial Starting volume ( ± 0.1ml) Ending volume ( ± 0.1ml) Volume used ( ± 0.2ml) 1 0.00 14.7 14.7 2 14.8 29.5 14.7 3 29.5 43.6 14.1 4 22.9 37.1 14.2 5 16.2 31.3 15.1 6 31.3 46.5 15.2 Reasoning for error: To measure the volume of NaOH put into the wine, the burette with a 0.1ml uncertainty was used. As the burette was only read once for the starting volume and once for the ending volume, the uncertainty is 0.1ml. For the sample calculation of the total volume used and the calculation for the uncertainty, refer to raw data table 1.