Question 1

Equal volumes of 0.020 M Ag⁺(aq)solution and 2.0 M NH₃(aq)solution are mixed.K_f for [Ag(NH₃)₂]⁺ is 1.6 × 10⁷.If trisodium arsenate is added so that the arsenate ion concentration is 0.10 M,will silver arsenate precipitate? What is Q_sp? K_sp for silver arsenate is 1.0 × 10^-22.

Accepted Answer

Given the K_sp for silver arsenate is significantly lower (1.0 × 10^-22) than the calculated Q_sp (which would be a result of the product of the concentrations of Ag+ and arsenate ions), and since the calculated Q_sp is much higher than K_sp, it would seem that silver arsenate should precipitate. However, the presence of a complexing agent (NH₃) can significantly increase the solubility of Ag+ ions, preventing the precipitation of silver arsenate. The correct answer must account for the complexation effect, which is not directly provided in the question, leading to a misunderstanding in the explanation. The correct approach involves calculating the actual concentration of free Ag+ ions in the presence of the complexing agent and arsenate, but without specific calculations or the effect of the complexing agent detailed in the options, the answer choice based on the provided information was incorrect. The correct answer should involve understanding that the presence of a strong complexing agent and the given conditions might not lead to precipitation, but the specific Q_sp calculation and comparison to K_sp are crucial for a definitive conclusion.

Question 2

Write the solubility product constant expression for the following salt: CoS(s).

Accepted Answer

The solubility product constant expression for CoS is written as [Co2+][S2-]. However, since CoS is a solid, we do not include it in the Ksp expression. Therefore, the expression only contains the concentration of the ions in solution, which are Co2+ and S2-. The correct expression for the Ksp of CoS is then [Co2+][S2-]. Option C represents that expression.

Question 3

Write the solubility product constant expression for the following salt: Ca(OH)₂(s).

Accepted Answer

The solubility product expression for Ca(OH)₂ is Ksp = [Ca²⁺][OH⁻]², reflecting the dissociation into one Ca²⁺ ion and two OH⁻ ions.

Question 4

What molar concentration of silver ion could exist in a solution in which the concentration of CrO₄^2- is 1.0 × 10^-4 M? (K_sp of Ag₂CrO₄ = 1.1 × 10^-12)

Accepted Answer

The answer of What molar concentration of silver ion could...

Question 5

Write the solubility product constant expression for the following salt: Ag₂SO₄(s).

Accepted Answer

The solubility product constant expression for Ag₂SO₄(s) can be written as [Ag⁺]²[SO₄^2-]. This expression includes the concentrations of ions from the salt dissolved in water, which are Ag^+,, SO₄, ^{2-, and}. The correct choice is B.

Question 6

The relationship between the molar concentration of silver ion in a saturated solution of silver phosphate and the solubility product constant for silver phosphate is ________.

Accepted Answer

Silver phosphate (Ag3PO4) dissociates into 3 Ag+ and 1 PO4^3-. The solubility product expression is Ksp = [Ag+]^3[PO4^3-]. If [Ag+] = x, then [PO4^3-] = x/3. Substituting these into the Ksp expression gives Ksp = (x)^3(x/3) = 27[Ag+]^4.

Question 7

Choose the compound that is most soluble in water.

Accepted Answer

KS (potassium sulfide) is the most soluble in water among the options given because potassium (K) is an alkali metal, and compounds formed with alkali metals tend to be highly soluble in water.

Question 8

At a temperature for which the solubility product constant of calcium carbonate is 4.7 × 10^-9,what mass of the salt will dissolve in 100 mL of water?

Accepted Answer

To determine the mass of calcium carbonate that will dissolve in 100 mL of water, we need to calculate the concentration of calcium ions and carbonate ions in the solution and use these concentrations to calculate the mass of calcium carbonate that can dissolve.

The solubility product constant expression for calcium carbonate is:

Ksp = [Ca2+][CO32-]

At equilibrium, the concentrations of Ca2+ and CO32- are the same, so we can write:

Ksp = [Ca2+]2 = [CO32-]2

Taking the square root of both sides, we get:

[Ca2+] = [CO32-] = sqrt(Ksp) = sqrt(4.7 × 10-9) = 6.86 × 10-5 M

The mass of calcium carbonate that can dissolve in 100 mL of water is given by:

mass = concentration x volume x molar mass

mass = (6.86 × 10-5 M) x (100 mL/1000) x (100.1 g/mol)

mass = 0.6895 mg

Round this answer to 0.69 mg. Therefore, the best choice is A).

Question 9

Write the solubility product constant expression for the following salt: PbC₂O₄(s).

Accepted Answer

The solubility product constant expression for a salt is written as the product of the concentrations of the ions, each raised to the power of its coefficient in the balanced equation for dissolution. The given salt does not provide clear chemical symbols or coefficients, but the correct format for a solubility product constant expression involves the ions in the salt, without coefficients in the expression itself.

Question 10

What is the composition of the precipitate formed when H₂S gas is bubbled through 1.0 litre of a solution of 0.010 M Zn²⁺,0.010 M Pb²⁺,and 0.010 M Mn²⁺,buffered at pH 2.0,until 0.10 mol of H₂S has been added? (K_sp values are: ZnS: 1.6 × 10^-23;MnS: 7.0 × 10^-16;PbS: 7.0 × 10^-29.For H₂S,K_a1 = 1.0 × 10^-7;K_a2 = 1.3 × 10^{-13 )}.

Accepted Answer

The correct answer is E.ZnS and PbS will precipitate out because their Ksp values are less than the [Zn2+][S2-] and [Pb2+][S2-] values, respectively. MnS will not precipitate out because its Ksp value is greater than the [Mn2+][S2-] value.

Question 11

The solubility product constant of PbI₂(s)is 7.1 × 10^-9.How many moles of PbI₂ will precipitate if 250 mL of a 0.200 M solution of NaI(aq)are added to 150 mL of 0.100 M solution of Pb(NO₃)₂(aq)? You may neglect hydrolysis.

Accepted Answer

When the solutions are mixed, the concentration of I⁻ is 0.125 M and Pb²⁺ is 0.0375 M. The reaction quotient Q = [Pb²⁺][I⁻]² = (0.0375)(0.125)² = 5.86 × 10⁻⁴, which is greater than Ksp, so PbI₂ will precipitate. The moles of PbI₂ precipitated is calculated by the difference in initial and equilibrium concentrations, resulting in 0.015 mol.

Question 12

A concentrated buffer of pH 8.0 is added to an equal volume of an aqueous solution that is 0.080 M in each of the ions Zn²⁺,Ni²⁺,and Mn²⁺.The expected precipitate would consist of ________.

Accepted Answer

The answer of A concentrated buffer of pH 8.0 is...

Question 13

Write the solubility product constant expression for the following salt: Ca₃(PO₄)₂(s).

Accepted Answer

The solubility product constant expression for Ca₃(PO₄)₂(s) is [Ca²⁺]³[PO₄^3-]² because the stoichiometric coefficients in the balanced chemical equation for the dissolution of Ca₃(PO₄)₂(s) are 3 for Ca²⁺ and 2 for PO₄^3-.

Question 14

Write the solubility product constant expression for the following salt: Na₂CO₃(s).

Accepted Answer

The solubility product expression for Na₂CO₃ is [Na⁺]²[CO₃²⁻] because it dissociates into 2 Na⁺ ions and 1 CO₃²⁻ ion.

Question 15

When 200 mL of 0.10 M BaCl₂(aq)is added to 100 mL of 0.30 M Na₂SO₄(aq),the number of moles of BaSO₄(solubility product = 1.1 × 10^-10)precipitated is ________.

Accepted Answer

The reaction between BaCl2 and Na2SO4 forms BaSO4 as a precipitate. Initially, we have 0.020 mol of Ba2+ (from 200 mL of 0.10 M BaCl2) and 0.030 mol of SO4^2- (from 100 mL of 0.30 M Na2SO4). Since BaSO4 has a 1:1 stoichiometry and is limited by the lesser amount of reactant, which is Ba2+, all 0.020 mol of Ba2+ will react to form BaSO4 precipitate.

Question 16

What is the minimum concentration of CN^-(aq)that will prevent the precipitation of AgX(s)from a solution that is 0.149 M in X^-(aq)and 0.0184 M in Ag⁺(aq)? (K_sp for AgX(s)= 5.2 × 10^-17;K_f for Ag(CN)₂^- = 5.6 × 10¹⁸)

Accepted Answer

To prevent the precipitation of AgX(s), the product of the concentrations of Ag+ and X- in solution must be less than the solubility product constant (Ksp) for AgX, which is 5.2 × 10^-17. The formation constant (Kf) for Ag(CN)2^- is 5.6 × 10^18, indicating that Ag+ will strongly complex with CN- to form Ag(CN)2^-. This complexation reduces the concentration of free Ag+ ions in solution, thus preventing the precipitation of AgX. The minimum concentration of CN- needed can be calculated using the Kf for Ag(CN)2^- and the initial concentration of Ag+. The correct calculation leads to a concentration of 3.1 × 10^-3 M CN-, which is option A.

Question 17

Consider an aqueous solution which is 0.020 M in Pb²⁺ and 0.20 M in Ag⁺.If concentrated aqueous potassium iodide solution (so that volume changes may be neglected)is added gradually with good stirring to this solution,which precipitate will form first? K_sp for PbI₂ = 7.1 × 10^-9;for AgI = 8.31 × 10^-17

Accepted Answer

To determine which precipitate will form first, we need to compare the solubility product (Ksp) values for PbI2 and AgI. The precipitate with the lower Ksp value will form first.

Ksp (PbI2) = 7.1 × 10⁻⁹ 
Ksp (AgI) = 8.31 × 10⁻¹⁷

AgI has a much lower Ksp value, which means it is less soluble and will form a precipitate first. Therefore, the answer is choice C, AgI.

Question 18

Write the solubility product constant for KAl(SO₄)₂(s)?

Accepted Answer

The solubility product constant (Ksp) for a compound is given by the product of the molar concentrations of its ions, each raised to the power of its coefficient in the balanced dissolution equation. For KAl(SO4)2·12H2O, the dissolution in water would produce K+, Al3+, and 2 SO4^2- ions. The correct expression for Ksp does not include the solid compound in the denominator and correctly accounts for the stoichiometry of the ions produced. Option D correctly represents this with [K+] × [Al3+] × [SO4^2-]^2, reflecting the dissolution of one formula unit of the compound into its constituent ions.

Question 19

What is the concentration of Ca²⁺ in ppm (mg/L)in cave water saturated with calcite (calcium carbonate,K_sp = 4.7 × 10^-9)?

Accepted Answer

The equilibrium reaction for Ca²⁺ with calcite can be written as: Ca²⁺ + CaCO3 ⇌ Ca2+ + 2HCO3- + S1U1P2- Using the given Ksp value of calcite (K_sp = 4.7 × 10^-9), we can set up an expression for the equilibrium constant (Keq) for the above reaction: Keq = ([Ca2+][HCO3-]2[S1U1P2-])/([Ca²⁺][CaCO3]) = K_sp Since the concentration of CaCO3 is typically much larger than the concentration of Ca²⁺, we can assume that the concentration of CaCO3 remains constant at its saturation concentration (which depends on factors such as temperature and pressure). This allows us to simplify the above expression to: ([Ca2+][HCO3-]2[S1U1P2-])/[Ca²⁺] = K_sp/[CaCO3] We are given the value of K_sp (4.7 × 10^-9), and we can assume a typical concentration for [HCO3-] in cave water (~200 ppm or mg/L). We also know the value of [Ca²⁺] that we want to find. Substituting these values and solving for [Ca2+], we get: [Ca2+] = [HCO3-]√(K_sp/[CaCO3][S1U1P2-][Ca²⁺]) We can convert this concentration of [Ca2+] to [Ca²⁺] using the stoichiometric coefficients from the balanced equation above: [Ca²⁺] = [Ca2+]/2 Plugging in the values, we get: [Ca²⁺] = [HCO3-]√(K_sp/[CaCO3][S1U1P2-][Ca2+]) [Ca²⁺] = (200 mg/L) √(4.7 × 10^-9/(100 mg/L)(1 mg/L)([Ca2+]/2)) [Ca²⁺] = (200 mg/L) √(4.7 × 10^-9/[Ca2+]) [Ca²⁺] = (200 mg/L) √(4.7 × 10^-9/(2 × 2.5 mg/L)) [Ca²⁺] ≈ 6.9 ppm Therefore, the answer is B) 6.9 ppm.

Question 20

The following table lists five compounds and their Ksp value.Which is least soluble?

Accepted Answer

The answer of The following table lists five compounds and...

Quiz 18: Solubility and Complex-Ion Equilibria

Equal volumes of 0.020 M Ag⁺(aq) solution and 2.0 M NH₃(aq) solution are mixed.K_f for [Ag(NH₃) ₂]⁺ is 1.6 × 10⁷.If trisodium arsenate is added so that the arsenate ion concentration is 0.10 M,will silver arsenate precipitate? What is Q_sp? K_sp for silver arsenate is 1.0 × 10^-22.

Write the solubility product constant expression for the following salt: CoS(s) .

Write the solubility product constant expression for the following salt: Ca(OH) ₂(s) .

What molar concentration of silver ion could exist in a solution in which the concentration of CrO₄^2- is 1.0 × 10^-4 M? (K_sp of Ag₂CrO₄ = 1.1 × 10^-12)

Write the solubility product constant expression for the following salt: Ag₂SO₄(s) .

The relationship between the molar concentration of silver ion in a saturated solution of silver phosphate and the solubility product constant for silver phosphate is ________.

Choose the compound that is most soluble in water.

At a temperature for which the solubility product constant of calcium carbonate is 4.7 × 10^-9,what mass of the salt will dissolve in 100 mL of water?

Write the solubility product constant expression for the following salt: PbC₂O₄(s) .

The solubility product constant of PbI₂(s) is 7.1 × 10^-9.How many moles of PbI₂ will precipitate if 250 mL of a 0.200 M solution of NaI(aq) are added to 150 mL of 0.100 M solution of Pb(NO₃) ₂(aq) ? You may neglect hydrolysis.

A concentrated buffer of pH 8.0 is added to an equal volume of an aqueous solution that is 0.080 M in each of the ions Zn²⁺,Ni²⁺,and Mn²⁺.The expected precipitate would consist of ________.

Write the solubility product constant expression for the following salt: Ca₃(PO₄) ₂(s) .

Write the solubility product constant expression for the following salt: Na₂CO₃(s) .

When 200 mL of 0.10 M BaCl₂(aq) is added to 100 mL of 0.30 M Na₂SO₄(aq) ,the number of moles of BaSO₄(solubility product = 1.1 × 10^-10) precipitated is ________.

What is the minimum concentration of CN^-(aq) that will prevent the precipitation of AgX(s) from a solution that is 0.149 M in X^-(aq) and 0.0184 M in Ag⁺(aq) ? (K_sp for AgX(s) = 5.2 × 10^-17;K_f for Ag(CN) ₂^- = 5.6 × 10¹⁸)

Write the solubility product constant for KAl(SO₄) ₂(s) ?

What is the concentration of Ca²⁺ in ppm (mg/L) in cave water saturated with calcite (calcium carbonate,K_sp = 4.7 × 10^-9) ?

The following table lists five compounds and their Ksp value.Which is least soluble?

Quiz 18: Solubility and Complex-Ion Equilibria

Equal volumes of 0.020 M Ag+(aq) solution and 2.0 M NH3(aq) solution are mixed.Kf for [Ag(NH3) 2]+ is 1.6 × 107.If trisodium arsenate is added so that the arsenate ion concentration is 0.10 M,will silver arsenate precipitate? What is Qsp? Ksp for silver arsenate is 1.0 × 10-22.

Write the solubility product constant expression for the following salt: CoS(s) .

Write the solubility product constant expression for the following salt: Ca(OH) 2(s) .

What molar concentration of silver ion could exist in a solution in which the concentration of CrO42- is 1.0 × 10-4 M? (Ksp of Ag2CrO4 = 1.1 × 10-12)

Write the solubility product constant expression for the following salt: Ag2SO4(s) .

The relationship between the molar concentration of silver ion in a saturated solution of silver phosphate and the solubility product constant for silver phosphate is ________.

Choose the compound that is most soluble in water.

At a temperature for which the solubility product constant of calcium carbonate is 4.7 × 10-9,what mass of the salt will dissolve in 100 mL of water?

Write the solubility product constant expression for the following salt: PbC2O4(s) .

The solubility product constant of PbI2(s) is 7.1 × 10-9.How many moles of PbI2 will precipitate if 250 mL of a 0.200 M solution of NaI(aq) are added to 150 mL of 0.100 M solution of Pb(NO3) 2(aq) ? You may neglect hydrolysis.

A concentrated buffer of pH 8.0 is added to an equal volume of an aqueous solution that is 0.080 M in each of the ions Zn2+,Ni2+,and Mn2+.The expected precipitate would consist of ________.

Write the solubility product constant expression for the following salt: Ca3(PO4) 2(s) .

Write the solubility product constant expression for the following salt: Na2CO3(s) .

When 200 mL of 0.10 M BaCl2(aq) is added to 100 mL of 0.30 M Na2SO4(aq) ,the number of moles of BaSO4 (solubility product = 1.1 × 10-10) precipitated is ________.

What is the minimum concentration of CN-(aq) that will prevent the precipitation of AgX(s) from a solution that is 0.149 M in X-(aq) and 0.0184 M in Ag+(aq) ? (Ksp for AgX(s) = 5.2 × 10-17;Kf for Ag(CN) 2- = 5.6 × 1018)

Write the solubility product constant for KAl(SO4) 2(s) ?

What is the concentration of Ca2+ in ppm (mg/L) in cave water saturated with calcite (calcium carbonate,Ksp = 4.7 × 10-9) ?

The following table lists five compounds and their Ksp value.Which is least soluble?

Equal volumes of 0.020 M Ag⁺(aq) solution and 2.0 M NH₃(aq) solution are mixed.K_f for [Ag(NH₃) ₂]⁺ is 1.6 × 10⁷.If trisodium arsenate is added so that the arsenate ion concentration is 0.10 M,will silver arsenate precipitate? What is Q_sp? K_sp for silver arsenate is 1.0 × 10^-22.

Write the solubility product constant expression for the following salt: Ca(OH) ₂(s) .

What molar concentration of silver ion could exist in a solution in which the concentration of CrO₄^2- is 1.0 × 10^-4 M? (K_sp of Ag₂CrO₄ = 1.1 × 10^-12)

Write the solubility product constant expression for the following salt: Ag₂SO₄(s) .

At a temperature for which the solubility product constant of calcium carbonate is 4.7 × 10^-9,what mass of the salt will dissolve in 100 mL of water?

Write the solubility product constant expression for the following salt: PbC₂O₄(s) .

The solubility product constant of PbI₂(s) is 7.1 × 10^-9.How many moles of PbI₂ will precipitate if 250 mL of a 0.200 M solution of NaI(aq) are added to 150 mL of 0.100 M solution of Pb(NO₃) ₂(aq) ? You may neglect hydrolysis.

A concentrated buffer of pH 8.0 is added to an equal volume of an aqueous solution that is 0.080 M in each of the ions Zn²⁺,Ni²⁺,and Mn²⁺.The expected precipitate would consist of ________.

Write the solubility product constant expression for the following salt: Ca₃(PO₄) ₂(s) .

Write the solubility product constant expression for the following salt: Na₂CO₃(s) .

When 200 mL of 0.10 M BaCl₂(aq) is added to 100 mL of 0.30 M Na₂SO₄(aq) ,the number of moles of BaSO₄(solubility product = 1.1 × 10^-10) precipitated is ________.

What is the minimum concentration of CN^-(aq) that will prevent the precipitation of AgX(s) from a solution that is 0.149 M in X^-(aq) and 0.0184 M in Ag⁺(aq) ? (K_sp for AgX(s) = 5.2 × 10^-17;K_f for Ag(CN) ₂^- = 5.6 × 10¹⁸)

Write the solubility product constant for KAl(SO₄) ₂(s) ?

What is the concentration of Ca²⁺ in ppm (mg/L) in cave water saturated with calcite (calcium carbonate,K_sp = 4.7 × 10^-9) ?