2022 IB Diploma Extended Essays

3.2 Data Processing Processed data table 1: Average volume of NaOH used to neutralise the 20ml of white wine in all 4 titration methods and the TA determined Method Average volume of NaOH (L) Uncertainty of Average NaOH Volume (L) Phenolphthalein 11.6 ×10 −3 ±2.07×10 −4 Bromothymol 11.3 ×10 −3 ±1.94×10 −4 Back titration 12.4 ×10 −3 ±4.00×10 −4 pH logger 14.7 ×10 −3 ±2.53×10 −4 Sample calculation for the average volume of NaOH using the data from Phenolphthalein: = ℎ = (12.2 ± 0.2) + (11.8 ± 0.2) + (11.0 ± 0.2) + (11.7 ± 0.2) + (11.2 ± 0.2) + (11.8 ± 0.2) 6 = 11.616 ± 1000 1.72% =0.0116 ± 1.72% ≈ 11.6×10 −3 ± 2.07×10 −4 Processed data table 2: Percentage Accuracy of the Titratable Acidity found through each titration method Method TA (mol − ) Uncertainty of TA (mol − ) Percentage Accuracy (%) Phenolphthalein 0.0290 ±4.97×10 −4 65.9 Bromothymol 0.0282 ±4.84×10 −4 64.1 Back titration 0.0310 ±1.00×10 −3 70.5 pH logger 0.0367 ±6.32×10 −4 83.4 Sample calculation for the TA of Tartaric acid using the data from Phenolphthalein: = (0.5× × ) = (0.5 × (11.6 × 10 −3 ± 2.07×10 −4 )×0.1) (20 ± 0.03ml) ÷ 1000L (5.80×10 −4 ±1.78%) 0.02 ± 0.0015% =0.02904 −3 ±1.7815% ≈ 0.0290 ± 4.97 × 10 −4 −3 Sample calculation for the Percentage Error of titration with Phenolphthalein: = ×100% = 00..002494 × 100% =65.9%