A student titrates 25.0 cm325.0\,\mathrm{cm^{3}}25.0cm3 of calcium hydroxide solution with 0.0500 mol/dm30.0500\,\mathrm{mol/dm^{3}}0.0500mol/dm3 hydrochloric acid. The balanced equation is:
Ca(OH)2+2HCl→CaCl2+2H2O \mathrm{Ca(OH)_{2} + 2HCl \rightarrow CaCl_{2} + 2H_{2}O} Ca(OH)2+2HCl→CaCl2+2H2OThe student records these titres:
| Titration | Titre (cm3\mathrm{cm^{3}}cm3) |
|---|---|
| Rough | 20.10 |
| 1 | 18.60 |
| 2 | 18.65 |
| 3 | 19.35 |
| 4 | 18.70 |
Relative atomic masses (ArA_rAr): Ca = 40.1, O = 16.0, H = 1.0
Calculate the concentration of the calcium hydroxide solution in g/dm3\mathrm{g/dm^{3}}g/dm3.
152 exam-style questions on OCR GCSE Chemistry 5.1 Monitoring chemical reactions, covering 5.1.1 The technique of titration, 5.1.2 Theoretical mass, percentage yield and atom economy, 5.1.3 Concentration of a solution in mol/dm3, 5.1.4 Concentration calculations and titration results, 5.1.5 Molar gas volume and volumes of gases in reactions, and 5.1.6 Choosing a reaction pathway. Each one has a worked solution and a mark scheme showing where the marks go.