A technician reacts potassium hydroxide with exactly enough nitric acid. The potassium nitrate solution formed is then made up to the required volume with water.
KOH(aq)+HNO3(aq)→KNO3(aq)+H2O(l)\mathrm{KOH(aq)} + \mathrm{HNO_3(aq)} \rightarrow \mathrm{KNO_3(aq)} + \mathrm{H_2O(l)}KOH(aq)+HNO3(aq)→KNO3(aq)+H2O(l)
| Quantity | Value |
|---|---|
| amount of potassium hydroxide | 0.0250 mol |
| final volume of solution | 200 cm3 |
| Element | K | N | O |
|---|---|---|---|
| Relative atomic mass | 39 | 14 | 16 |
Calculate the concentration of potassium nitrate in the completed solution, in g dm−3\mathrm{g\,dm^{-3}}gdm−3.
142 exam-style questions on Edexcel GCSE Chemistry 2.6 Calculations involving masses, covering 2.6.1 Relative formula mass and percentage composition, 2.6.2 Empirical and molecular formulae, 2.6.3 Conservation of mass, 2.6.4 Reacting masses and concentration in g dm⁻³, 2.6.5 The mole and the Avogadro constant, and 2.6.6 Limiting reactants and stoichiometry. Each one has a worked solution and a mark scheme showing where the marks go.