A student carries out an acid-alkali titration four times to determine the volume of sulfuric acid needed to neutralise sodium hydroxide.
The volumes recorded from the student's investigation are shown in the table below.
| Rough | Titration 1 | Titration 2 | Titration 3 | |
|---|---|---|---|---|
| Volume of acid used (cm3\text{cm}^3cm3) | 22.80 | 21.60 | 22.10 | 21.70 |
Which two volumes should the student use to calculate the mean volume?
Rough and Titration 2
Titration 1 and Titration 2
Titration 1 and Titration 3
Titration 2 and Titration 3
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.