Each test in an investigation uses a 20.0 cm320.0\,\mathrm{cm^{3}}20.0cm3 portion from one bottle. The technician needs each test to receive the greatest possible amount in moles of dissolved solute.
The preparation details for the four bottles are shown.
| Bottle | Solute | Mass of solute (g) | Volume of solution (cm3\mathrm{cm^{3}}cm3) |
|---|---|---|---|
| W | calcium nitrate, Ca(NO3)2\mathrm{Ca(NO_3)_2}Ca(NO3)2 | 16.41 | 250 |
| X | sodium nitrate, NaNO3\mathrm{NaNO_3}NaNO3 | 4.25 | 100 |
| Y | potassium nitrate, KNO3\mathrm{KNO_3}KNO3 | 15.17 | 250 |
| Z | ammonium nitrate, NH4NO3\mathrm{NH_4NO_3}NH4NO3 | 10.40 | 200 |
Relative formula mass (MrM_rMr): Ca(NO3)2\mathrm{Ca(NO_3)_2}Ca(NO3)2 = 164.1 NaNO3\mathrm{NaNO_3}NaNO3 = 85.0 KNO3\mathrm{KNO_3}KNO3 = 101.1 NH4NO3\mathrm{NH_4NO_3}NH4NO3 = 80.0
Which bottle should the technician use for the tests?
Bottle X
Bottle Z
Bottle W
Bottle Y
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.