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17 Additional Aspects of Solutions to Exercises Aqueous Equilibria (c) NaNO₃ has no common ions, nor does it enter into acid-base or complex ion equilibria with or it does not affect the solubility of BaCO₃. This behavior is shown in the center diagram. 17.10 Analyze/Plan. Calculate the molarity of the solution assuming all Ca(OH)₂(s) dissolves. Use this concentration along with the Ksp expression for Ca(OH)₂ to answer the questions. (a) = 0.370 0.500 Ca(OH)₂ L soln 74.093 1 mol g Ca(OH)₂ Ca(OH)₂ = 0.00998745 = 0.00999 M [Ca²⁺] = 0.00999 M; [OH⁻] = 2(0.00998745) = 0.0199749 = 0.0200 M; Ksp = Calculate the reaction quotient using the calculated molarities. If it is equal to or greater than Ksp, the resulting solution is saturated. Q = = 3.99 10⁻⁶. Q Ksp (6.5 10⁻⁶) and Ca(OH)₂ precipitates. (iv) A common ion with a different concentration; [Ca²⁺] = (0.10 + 0.00999)/2 = 0.0550 = 0.055 M. Q = = 5.49 10⁻⁶. Q ≈ Ksp (6.5 the solution is very nearly saturated, but no precipitate forms. 17.11 A metal hydroxide that is soluble at very low and very high pH's, that is, in strong acid or strong base, is called amphoteric. 17.12 According to Figure 17.23, the two precipitating agents are 6 M (first) and in 0.2 M (second). Cation A = Ag+ (precipitates as Cation B = Cu+ (precipitates as CuS, acid insoluble) Cation = Ni²⁺ (remains in acidic solution) Common-Ion Effect (section 17.1) 17.13 (a) The extent of ionization of a weak electrolyte is decreased when a strong electrolyte containing an ion in common with the weak electrolyte is added to it. (b) NaNO₂ 505