Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can describe a saturated solution as a dynamic equilibrium in which dissolving and precipitating happen at equal rates. (Guide: “Dissolving is an equilibrium too”, Figure 1)
- I can explain why adding more solid to a saturated solution does not change the ion concentrations. (Guide: Common misconceptions; Practice Q7(b))
- I can explain the difference between molar solubility (mol L⁻¹) and K_sp. (Guide: “Molar solubility and how it links to K_sp”)
- I can link a K_sp greater than 1 to a soluble salt, such as any sodium, potassium, ammonium or nitrate salt. (Guide: “Connecting K_sp to the solubility rules”; Practice Q4)
Calculation
- I can write the K_sp expression for any ionic solid from its formula, leaving out the solid. (Practice Q1)
- I can write K_sp in terms of s for any ion ratio, using (xs)ˣ(ys)ʸ. (Practice Q2)
- I can calculate the molar solubility of a salt from its K_sp and convert it to g L⁻¹ or a mass in a given volume. (Guide: Worked example 1; Practice Q5)
- I can calculate K_sp from a measured solubility in grams per volume. (Guide: Worked example 2)
- I can calculate K_sp from the measured concentration of just one ion. (Practice Q6(a), (b))
- I can use Q and K_sp, after allowing for dilution, to predict whether a precipitate forms when two solutions are mixed. (Guide: “Will a precipitate form?”; Practice Q6(c))
Reasoning
- I can rank salts by solubility, comparing K_sp directly only when their ion ratios match and calculating s when they do not. (Guide: Worked example 3; Practice Q3)
- I can evaluate a claim that equal K_sp values mean equal solubilities. (Practice Q7(a))
- I can state the assumptions behind a K_sp calculation. (Guide: “Assumptions in these calculations”; Revision notes)
All ticked? Move on to Topic 7.12, Common-Ion Effect, or return to the course roadmap.