Solubility - AP Chemistry

1. Identify the solubility rule for phosphates.

   Phosphates are generally insoluble except for those of alkali metals and $NH_4^+$. Only alkali metals and ammonium form soluble phosphates.

2. What is the solubility rule for chlorides?

   Chlorides are generally soluble except for $AgCl$, $PbCl_2$, and $Hg_2Cl_2$. These three chlorides are notable exceptions to solubility.

3. What is Henry's Law?

   Henry's Law states that the solubility of a gas is directly proportional to its partial pressure. This describes the pressure-solubility relationship for gases.

4. What is the solubility product constant ($K_{sp}$)?

   $K_{sp}$ is the product of the concentrations of the ions each raised to the power of its coefficient. This equilibrium expression applies to saturated solutions.

5. Identify the relationship between solubility and ionic strength.

   Solubility can increase with increasing ionic strength due to the salt effect. More ions in solution can affect solubility equilibria.

6. What is the definition of solubility?

   Solubility is the maximum amount of solute that can dissolve in a solvent at a given temperature. This defines the equilibrium limit of dissolution.

7. Identify the effect of adding a soluble salt on solubility.

   Adding a soluble salt can increase ionic strength, potentially increasing solubility. The salt effect can enhance solubility through ionic interactions.

8. What does it mean if a solution is dilute?

   A dilute solution contains a small amount of solute relative to the solvent. This describes low solute concentration relative to capacity.

9. Identify the unit for solubility.

   Solubility is often expressed in moles per liter (mol/L) or grams per liter (g/L). These are the standard units for expressing solubility.

10. State the formula for molarity.

    $M = \frac{n}{V}$ where $M$ is molarity, $n$ is moles of solute, $V$ is volume in liters. This is the fundamental concentration formula.

11. State the solubility rule for carbonates.

    Carbonates are generally insoluble except for those of alkali metals and $NH_4^+$. Only alkali metals and ammonium form soluble carbonates.

12. What does a saturated solution mean?

    A saturated solution contains the maximum concentration of solute that can dissolve at a given temperature. This represents equilibrium between dissolved and undissolved solute.

13. What is meant by a supersaturated solution?

    A supersaturated solution contains more solute than what is soluble at a given temperature. This metastable state exceeds normal solubility limits.

14. What is the solubility rule for nitrates?

    Nitrates are generally soluble without exceptions. All nitrate compounds dissolve readily in water.

15. Find the molarity of a solution with 0.5 moles of solute in 2 L of solution.

    Molarity $M = 0.25 \text{ mol/L}$. Using $M = \frac{n}{V} = \frac{0.5}{2}$.

16. Find the solubility of a salt given $K_{sp} = 1.0 \times 10^{-10}$ for $AB_2$.

    Solubility $S = \sqrt[3]{\frac{K_{sp}}{4}}$. For $AB_2$: $K_{sp} = [A^{2+}][B^-]^2 = 4S^3$.

17. State the solubility rule for sulfides.

    Sulfides are generally insoluble except for those of alkali metals and $NH_4^+$. Only alkali metals and ammonium form soluble sulfides.

18. What is the definition of a solution?

    A solution is a homogeneous mixture of two or more substances. Solutions have uniform composition throughout.

19. Determine if $NaCl$ is soluble in water.

    $NaCl$ is soluble in water. Sodium chloride follows the alkali metal solubility rule.

20. State the solubility rule for sulfates.

    Sulfates are generally soluble except for $BaSO_4$, $PbSO_4$, and $CaSO_4$. These three sulfates have low solubility values.

21. What is the common ion effect?

    The common ion effect is the decrease in solubility of a salt when a common ion is added. Le Chatelier's principle explains this solubility decrease.

22. What is the role of a temperature curve in solubility?

    A temperature curve shows how solubility changes with temperature. These curves plot solubility versus temperature data.

23. Describe an unsaturated solution.

    An unsaturated solution can dissolve more solute at a given temperature. The solution can accommodate additional solute.

24. What is the role of a solvent in solubility?

    A solvent dissolves the solute, forming a solution. The solvent provides the medium for dissolution.

25. Determine if $AgCl$ is soluble or insoluble.

    $AgCl$ is insoluble in water. Silver chloride follows the chloride exception rule.

26. How does pressure affect gas solubility in liquids?

    Gas solubility in liquids increases with increasing pressure. Higher pressure forces more gas molecules into solution.

27. How does solubility relate to concentration?

    Solubility is the maximum concentration of solute that can dissolve. Solubility sets the upper limit for solution concentration.

28. How is solubility affected by particle size?

    Smaller particles dissolve faster, increasing the rate but not the solubility. Surface area affects dissolution rate, not total solubility.

29. What is the solubility rule for nitrates?

    Nitrates are generally soluble without exceptions. All nitrate compounds dissolve readily in water.

30. Which solubility rule applies to hydroxides?

    Hydroxides are generally insoluble except for alkali metals and $Ba(OH)_2$. These are the only hydroxides with significant solubility.

31. How do you calculate $K_{sp}$ for $CaF_2$?

    $K_{sp} = [Ca^{2+}][F^-]^2$. The stoichiometry shows 1:2 ion ratio in the expression.

32. How does the presence of a common ion affect solubility?

    The presence of a common ion decreases the solubility of a compound. The equilibrium shifts left by Le Chatelier's principle.

33. What is the definition of a solute?

    A solute is a substance dissolved in another substance, forming a solution. The solute is the dissolved component of a solution.

34. What is the relationship between solubility and temperature for most solids?

    Solubility of most solids increases with increasing temperature. Higher temperature provides energy to break intermolecular forces.

35. Identify the effect of adding a soluble salt on solubility.

    Adding a soluble salt can increase ionic strength, potentially increasing solubility. The salt effect can enhance solubility through ionic interactions.

36. What is the effect of temperature on gas solubility?

    Gas solubility decreases with increasing temperature. Higher kinetic energy reduces gas-liquid interactions.

37. What does a saturated solution mean?

    A saturated solution contains the maximum concentration of solute that can dissolve at a given temperature. This represents equilibrium between dissolved and undissolved solute.

38. How does stirring affect solubility?

    Stirring increases the rate of solute dissolving, but not the solubility. Stirring affects dissolution rate, not equilibrium solubility.

39. What is a precipitation reaction?

    A precipitation reaction is when two solutions combine to form an insoluble solid. This occurs when the reaction quotient exceeds $K_{sp}$.

40. Which ions generally form soluble compounds?

    Nitrates ($NO_3^-$), acetates ($CH_3COO^-$) and most alkali metals are generally soluble. These ions form highly soluble compounds with most anions.

41. What is a colligative property related to solubility?

    Freezing point depression is a colligative property related to solubility. Colligative properties depend on particle number, not identity.

42. Which factor affects solubility: temperature or pressure?

    Both temperature and pressure affect solubility. Both factors influence how much solute dissolves.

Study these flashcards