A laboratory prepares a batch of dilute hydrochloric acid for use in an experiment.
The batch can be used only if its hydrogen chloride concentration is between 7.20 g/dm37.20\,\mathrm{g/dm^{3}}7.20g/dm3 and 7.40 g/dm37.40\,\mathrm{g/dm^{3}}7.40g/dm3, inclusive.
A titration gives a hydrogen chloride concentration of 0.190 mol/dm30.190\,\mathrm{mol/dm^{3}}0.190mol/dm3.
The accurate titres used to determine this concentration are shown in the table.
| Titration | Titre (cm3\mathrm{cm^{3}}cm3) |
|---|---|
| 1 | 19.00 |
| 2 | 19.05 |
| 3 | 19.00 |
Relative atomic masses (ArA_rAr): H = 1.0, Cl = 35.5
Evaluate whether this batch of hydrochloric acid should be used in the experiment.
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.