A student carried out a titration to determine the concentration of a sodium hydroxide solution using dilute hydrochloric acid.
Their results are shown in the table below.
| Rough | Titration 1 | Titration 2 | Titration 3 | |
|---|---|---|---|---|
| Final burette reading in cm3\text{cm}^3cm3 | 23.10 | 21.90 | 43.10 | 22.00 |
| Initial burette reading in cm3\text{cm}^3cm3 | 0.50 | 0.30 | 21.90 | 0.50 |
| Volume of acid added in cm3\text{cm}^3cm3 | 22.60 | 21.60 | 21.20 | 21.50 |
Calculate the mean (accurate) volume of hydrochloric acid that should be used in subsequent concentration calculations.
157 exam-style questions on Edexcel GCSE Chemistry 6.2 Quantitative analysis, covering 6.2.1 Concentration in mol dm⁻³ and titration calculations, 6.2.2 Percentage yield and why actual yield falls short, 6.2.3 Atom economy of a reaction, 6.2.4 Choosing a reaction pathway, and 6.2.5 Molar volume of gases and Avogadro's law. Each one has a worked solution and a mark scheme showing where the marks go.