A quality control chemist is determining the concentration of ethanoic acid in a household cleaning solution. They titrate 20.0 cm3 samples of the solution against a standard sodium hydroxide solution. The burette is filled with the sodium hydroxide solution.
The results of the four titrations carried out are recorded in Table 1.
Table 1
| Titration 1 (Rough) | Titration 2 | Titration 3 | Titration 4 | |
|---|---|---|---|---|
| Final burette reading / cm3\text{cm}^3cm3 | 16.50 | 17.00 | 32.85 | 15.90 |
| Initial burette reading / cm3\text{cm}^3cm3 | 0.00 | 1.25 | 17.00 | 0.10 |
| Volume of NaOH used / cm3\text{cm}^3cm3 | 16.50 | 15.75 | 15.85 | 15.80 |
In this analysis, concordant results are defined as volumes of sodium hydroxide used that are within 0.10 cm3 of each other.
Calculate the mean volume of sodium hydroxide solution required, using only the concordant results.
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