15.3 Multiple equilibria  (Page 6/8)

A saturated solution of a slightly soluble electrolyte in contact with some of the solid electrolyte is said to be a system in equilibrium. Explain. Why is such a system called a heterogeneous equilibrium?

Calculate the equilibrium concentration of Ni ²⁺ in a 1.0- M solution [Ni(NH ₃ ) ₆ ](NO ₃ ) ₂ .

Calculate the equilibrium concentration of Zn ²⁺ in a 0.30- M solution of $\text{Zn}{(\text{CN})}_4{}^{\text{2−}}.$

Calculate the equilibrium concentration of Cu ²⁺ in a solution initially with 0.050 M Cu ²⁺ and 1.00 M NH ₃ .

Calculate the equilibrium concentration of Zn ²⁺ in a solution initially with 0.150 M Zn ²⁺ and 2.50 M CN ^– .

Calculate the Fe ³⁺ equilibrium concentration when 0.0888 mole of K ₃ [Fe(CN) ₆ ] is added to a solution with 0.0.00010 M CN ^– .

Calculate the Co ²⁺ equilibrium concentration when 0.100 mole of [Co(NH ₃ ) ₆ ](NO ₃ ) ₂ is added to a solution with 0.025 M NH ₃ . Assume the volume is 1.00 L.

The equilibrium constant for the reaction ${\text{Hg}}^{\text{2+}}(aq)+2{\text{Cl}}^{\text{−}}(aq)\rightleftharpoons {\text{HgCl}}_2(aq)$ is 1.6 $\times$ 10 ¹³ . Is HgCl ₂ a strong electrolyte or a weak electrolyte? What are the concentrations of Hg ²⁺ and Cl ^– in a 0.015- M solution of HgCl ₂ ?

Calculate the molar solubility of Sn(OH) ₂ in a buffer solution containing equal concentrations of NH ₃ and ${\text{NH}}_4{}^{\mathrm{+}}.$

Calculate the molar solubility of Al(OH) ₃ in a buffer solution with 0.100 M NH ₃ and 0.400 M ${\text{NH}}_4{}^{\mathrm{+}}.$

What is the molar solubility of CaF ₂ in a 0.100- M solution of HF? K _a for HF = 7.2 $\times$ 10 ^–4 .

What is the molar solubility of BaSO ₄ in a 0.250- M solution of NaHSO ₄ ? K _a for ${\text{HSO}}_4{}^{\text{−}}$ = 1.2 $\times$ 10 ^–2 .

What is the molar solubility of Tl(OH) ₃ in a 0.10- M solution of NH ₃ ?

What is the molar solubility of Pb(OH) ₂ in a 0.138- M solution of CH ₃ NH ₂ ?

A solution of 0.075 M CoBr ₂ is saturated with H ₂ S ([H ₂ S] = 0.10 M ). What is the minimum pH at which CoS begins to precipitate?

$\text{CoS}(s)\rightleftharpoons {\text{Co}}^{\text{2+}}(aq)+{\text{S}}^{\text{2−}}(aq)K_{\text{sp}}=4.5\times {10}^{\text{−27}}$

${\text{H}}_2\text{S}(aq)+2{\text{H}}_2\text{O}(l)\rightleftharpoons 2{\text{H}}_3{\text{O}}^{\text{+}}(aq)+{\text{S}}^{\text{2−}}(aq)K=1.0\times {10}^{\text{−26}}$

A 0.125- M solution of Mn(NO ₃ ) ₂ is saturated with H ₂ S ([H ₂ S] = 0.10 M ). At what pH does MnS begin to precipitate?

$\text{MnS}(s)\rightleftharpoons {\text{Mn}}^{\text{2+}}(aq)+{\text{S}}^{\text{2−}}(aq)K_{\text{sp}}=4.3\times {10}^{\text{−22}}$

${\text{H}}_2\text{S}(aq)+2{\text{H}}_2\text{O}(l)\rightleftharpoons 2{\text{H}}_3{\text{O}}^{\text{+}}(aq)+{\text{S}}^{\text{2−}}(aq)K=1.0\times {10}^{\text{−26}}$

Calculate the molar solubility of BaF ₂ in a buffer solution containing 0.20 M HF and 0.20 M NaF.

Calculate the molar solubility of CdCO ₃ in a buffer solution containing 0.115 M Na ₂ CO ₃ and 0.120 M NaHCO ₃

To a 0.10- M solution of Pb(NO ₃ ) ₂ is added enough HF( g ) to make [HF] = 0.10 M .

(a) Does PbF ₂ precipitate from this solution? Show the calculations that support your conclusion.

(b) What is the minimum pH at which PbF ₂ precipitates?

Calculate the concentration of Cd ²⁺ resulting from the dissolution of CdCO ₃ in a solution that is 0.010 M in H ₂ CO ₃ .

Both AgCl and AgI dissolve in NH ₃ .

(a) What mass of AgI dissolves in 1.0 L of 1.0 M NH ₃ ?

(b) What mass of AgCl dissolves in 1.0 L of 1.0 M NH ₃ ?

Calculate the volume of 1.50 M CH ₃ CO ₂ H required to dissolve a precipitate composed of 350 mg each of CaCO ₃ , SrCO ₃ , and BaCO ₃ .