Question 1

If 500 mL of 1.4 × 10^-6 M AgNO₃ is mixed with 500 mL of 1.4 × 10^-6 M NaBr, what will occur? For AgBr, K_sp = 5 × 10^-13.

Accepted Answer

The answer of If 500 mL of 1.4 × 10^-6...

Question 2

Given the following equilibrium constants, Zn4IO₃)₂ K_sp = $3.9 \times 10 - 6$ Zn(NH₃)₄²⁺ K_f = $2.9 \times 10 ^ { 9 }$ determine K for the dissolution of the sparingly soluble salt Zn(IO₃)₂ in aqueous ammonia (shown below). Zn(IO₃)₂(s) + 4NH₃(aq) ? Zn(NH₃)₄²⁺(aq) + 2IO₃^-(aq)

Accepted Answer

The equilibrium constant K for the dissolution reaction is calculated by multiplying the Ksp of Zn(IO3)2 and the Kf of Zn(NH3)4^2+. Therefore, K = (3.9 × 10^-6) × (2.9 × 10^9) = 1.1 × 10^4.

Question 3

What is the minimum mass of Na₂CO₃ (molar mass = 105.990 g/mol) that must be added to 43.4 mL of a 1.0 × 10^-4 M AgNO₃ solution in order for precipitation to occur? The K_sp of Ag₂CO₃ is 8.6 × 10^-12. Assume no volume change occurs upon addition of Na₂CO₃.

Accepted Answer

The answer of What is the minimum mass of Na₂CO₃...

Question 4

What is the minimum concentration of Cd²⁺ required to begin precipitating Cd(OH)₂(s) in a solution buffered at pH 10.83? The K_sp of Cd(OH)₂ is 5.3 × 10^-15 and K_w = 1.01 × 10^-14.

Accepted Answer

The answer of What is the minimum concentration of Cd²⁺...

Question 5

Calculate the molar concentration of uncomplexed Zn²⁺(aq) in a solution that contains 0.17 M Zn(NH₃)₄²⁺ and 0.3775 M NH₃ at equilibrium. K_f for Zn(NH₃)₄²⁺ is $2.9 \times 10 ^ { 9 }$ .

Accepted Answer

The answer of Calculate the molar concentration of uncomplexed Zn²⁺(aq)...

Question 6

In which of the following solutions would silver(I) phosphate, Ag₃PO₄, be least soluble?

Accepted Answer

Ag+ ions will react with NO3- ions to form AgNO3, which is insoluble. Therefore, option B, which contains Ag+ ions, will be the least soluble solution.

Question 7

Consider the reaction Cu²⁺(aq) + 4 NH₃(aq) $\leftrightharpoons$ Cu(NH₃)₄²⁺(aq) K_f = 2.1 × 10¹³ If the K_sp for Cu(OH)₂ is 2.2 × 10^-20, what is the value of the equilibrium constant, K, for the reaction below? Cu(NH₃)₄²⁺(aq) + 2 OH^-(aq) $\leftrightharpoons$ Cu(OH)₂(s) + 4 NH₃(aq)

Accepted Answer

The answer of Consider the reaction Cu²⁺(aq) + 4 NH₃(aq) $\leftrightharpoons$...

Question 8

An aqueous solution contains 0.010 M bromide ion (Br^-) and 0.010 M iodide ion (I^-). If silver ions (Ag⁺) are added to the solution until silver bromide just begins to precipitate, what are the concentrations of silver ions and iodide ions? (K_sp of AgBr = 5.4 × 10^-13 and K_sp of AgI = 8.5 × 10^-17)

Accepted Answer

The precipitation reaction for AgBr is:

AgS1U1P1+S1S1P0 + BrS1U1P1-S1S1P0 → AgBrS1U1P1↓ + BrS1U1P1-S1S1P0

The equilibrium constant for this reaction is:

KS1U1B1spS1U1B0 = [AgBr][Br-]/[Ag+]

At the point where AgBr begins to precipitate, the concentration of Ag+ ions will be equal to the product of the equilibrium constant and the concentration of Br- ions:

[Ag+] = KS1U1B1spS1U1B0[Br-]

Substituting the given values:

[Ag+] = (5.4 × 10S1U1P1-13S1S1P0)(0.010 M) = 5.4 × 10S1U1P1-14S1S1P0 M

Similarly, the precipitation reaction for AgI is:

AgS1U1P1+S1S1P0 + IS1U1P1-S1S1P0 → AgIS1U1P1↓ + IS1U1P1-S1S1P0

The equilibrium constant for this reaction is:

KS1U1B1spS1U1B0 = [AgI][I-]/[Ag+]

At the point where AgI begins to precipitate, the concentration of Ag+ ions will be equal to the product of the equilibrium constant and the concentration of I- ions:

[Ag+] = KS1U1B1spS1U1B0[I-]

Substituting the given values:

[Ag+] = (8.5 × 10S1U1P1-17S1S1P0)(0.010 M) = 8.5 × 10S1U1P1-18S1S1P0 M

Thus, the concentration of Ag+ ions is lower in the precipitation of AgBr than in the precipitation of AgI. At the point where AgBr begins to precipitate, all of the Br- ions will have reacted with Ag+ ions, which leaves only I- ions in solution. Therefore, the concentration of I- ions will be equal to the initial concentration of I- ions:

[IS1U1P1-S1S1P0] = 0.010 M

Choice C is the best answer because it gives the correct concentrations for [Ag+] and [IS1U1P1-S1S1P0].

Question 9

Two important biological buffer systems control pH in the range of 6.9 to 7.4. These buffer systems are H₂CO₃/HCO₃^- and _____.

Accepted Answer

The answer of Two important biological buffer systems control pH...

Question 10

The following anions can be separated by precipitation as silver salts: Cl^-, Br^-, I^-, and CrO₄^2-. If silver ions (Ag⁺) are added to a solution containing the four anions that are at concentrations of 0.10 M, in what order will they precipitate? $$\begin{array} { l l } \text { Compound } & K _ { \mathrm { sp } } \ \hline \mathrm { AgCl } & 1.8 \times 10 ^ { - 10 } \ \mathrm { Ag } _ { 2 } \mathrm { CrO } _ { 4 } & 1.1 \times 10 ^ { - 12 } \ \mathrm { AgBr } & 5.4 \times 10 ^ { - 13 } \ \mathrm { AgI } & 8.5 \times 10 ^ { - 17 } \end{array}$$

Accepted Answer

The order of precipitation is determined by the solubility product constants (Ksp). The compound with the smallest Ksp will precipitate first. AgI has the smallest Ksp, followed by AgBr, AgCl, and finally Ag2CrO4.

Question 11

What is the maximum hydroxide-ion concentration that a 0.019 M MgCl₂ solution could have without causing the precipitation of Mg(OH)₂? For Mg(OH)₂, K_sp = 1.8 × 10^-11.

Accepted Answer

The answer of What is the maximum hydroxide-ion concentration that...

Question 12

Given the two equilibria below, Ag(NH₃)₂⁺(aq) $\rightleftharpoons$$\leftrightharpoons$ Ag⁺(aq) + 2NH₃(aq); K_d = 5.9 × 10^-8 AgCN(s) $\rightleftharpoons$ Ag⁺(aq) + CN?(aq); K_sp = $2.2 \times 10 ^ { - 16 }$ what is K for the following equilibrium? AgCN(s) + 2NH₃(aq) $\rightleftharpoons$ Ag(NH₃)₂⁺(aq) + CN^-(aq)

Accepted Answer

The equilibrium constant K for the reaction can be found by dividing K_sp by K_d: $K = \frac{K_{sp}}{K_d} = \frac{2.2 \times 10^{-16}}{5.9 \times 10^{-8}} = 3.7 \times 10^{-9}$.

Question 13

What is the molar solubility of solid iron(III) hydroxide, Fe(OH)₃, in a solution that is buffered to a pH of 2.50 at 25 °C? The K_sp of Fe(OH)₃ is 6.3 × 10^-38 at 25 °C.

Accepted Answer

The answer of What is the molar solubility of solid...

Question 14

A 5.0 × 10^-4 M solution of MnSO₄ is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? The K_sp of Mn(OH)₂ is 2.0 × 10^-13 and K_w = 1.01 × 10^-14.

Accepted Answer

The answer of A 5.0 × 10^-4 M solution of...

Question 15

Suppose 50.00 mL of 2.0 × 10^-5 M Fe(NO₃)₃ is added to 50.00 mL of 2.0 ×10^-4 M KIO₃. Which of the following statements is true? For Fe(IO₃)₃, K_sp = 1.0 × 10^-14.

Accepted Answer

The answer of Suppose 50.00 mL of 2.0 × 10^-5...

Question 16

What is the molar solubility of Mn(OH)₂(s) in a solution that is buffered at pH 8.00 at 25 °C? The K_sp of Mn(OH)₂ is 1.9 × 10^-13 at 25 °C.

Accepted Answer

The answer of What is the molar solubility of Mn(OH)₂(s)...

Question 17

What is the value of the dissociation constant, K_dissociation, for the complex ion Zn(NH₃)₄²⁺? (K_f = 2.9 × 10⁹)

Accepted Answer

The answer of What is the value of the dissociation...

Question 18

Given the following reactions, AgBr(s) $\leftrightharpoons$ Ag⁺(aq) + Br^-(aq) K_sp = 5.4 × 10^-13 Ag⁺(aq) + 2 CN^-(aq) $\leftrightharpoons$ Ag(CN)₂^-(aq) K_f = 1.2 × 10²¹ Determine the equilibrium constant for the reaction below. AgBr(s) + 2 CN^-(aq) $\leftrightharpoons$ Ag(CN)₂^-(aq) + Br^-(aq)

Accepted Answer

The equilibrium constant for the overall reaction is the product of the individual equilibrium constants: K = K_sp × K_f = (5.4 × 10^-13) × (1.2 × 10²¹) = 6.5 × 10⁸.

Question 19

The concentration of Pb²⁺ in an aqueous solution is 5.5 × 10^-3 M. What concentration of SO₄^2- is required to begin precipitating PbSO₄? The K_sp of PbSO₄ is 2.5 × 10^-8.

Accepted Answer

The Ksp of PbSO4 is given as 2.5 × 10^-8. To find the concentration of SO4^2- required to begin precipitating PbSO4, we use the formula Ksp = [Pb^2+][SO4^2-]. Given [Pb^2+] = 5.5 × 10^-3 M, we rearrange the formula to find [SO4^2-] = Ksp / [Pb^2+] = (2.5 × 10^-8) / (5.5 × 10^-3) = 4.5 × 10^-6 M.

Question 20

What is the concentration of Cd²⁺(aq) in a mixture of 0.014 mol Cd(NO₃)₂ and 1.0 mol NH₃ diluted to 1.00 L? For Cd(NH₃)₄²⁺, K_f = 1.0 × 10⁷.

Accepted Answer

First, write out the balanced chemical equation:
Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0 + S1U1B1O1(1) → CdS1U1P12+S1S1P0(aq) + N1U1B1H1S1U1B12S1U1B0

We are given the initial concentrations of Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0 and NHS1U1B13S1U1B0, and the value of Kf for CdS1U1P12+S1S1P0(aq).

Since Cd(NHS1U1B13S1U1B0)S1U1B14S1U1B0S1U1P12+S1S1P0 is an insoluble salt, we can assume that the formation of CdS1U1P12+S1S1P0(aq) is complete and that all of the Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0 has been converted to CdS1U1P12+S1S1P0(aq).

Next, we need to calculate the concentration of CdS1U1P12+S1S1P0(aq) in the mixture.
Let x be the molar concentration of CdS1U1P12+S1S1P0(aq).

Then the concentration of [Cd2+] and [S2-] in the mixture will both be x.

The concentration of [NHS1U1B13S1U1B0] in the mixture will be (1.0 mol/L - 0.014 mol/L) = 0.986 mol/L.

Using the balanced chemical equation and the value of Kf, we can set up an ICE table:

Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0 + S1U1B1O1(1) → CdS1U1P12+S1S1P0(aq) + N1U1B1H1S1U1B12S1U1B0
I       0.014 mol             1.0 mol                  0              0
C    - 0.014 mol         - 0.014 mol         + x                + x
E         0                  0.986 mol            x                x

The Kf expression for CdS1U1P12+S1S1P0(aq) is:

Kf = ([Cd2+][S2-])/[CdS1U1P12+S1S1P0(aq)]

This can be rearranged to solve for x:

x2 = (Kf[Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0][S1U1B1O1(1)]) / (1+[Cd(NHS1U1B13S1U1B0)S1U1B12S1U1B0])

Substituting the given values:

x2 = [(1.0 × 10S1U1P17S1S1P0)(0.014 mol/L)(1.0 mol/L)] / (1+0.014 mol/L) = 1.79 × 10S1U1P1-10S1S1P0

x = 1.34 × 10S1U1P1-5S1S1P0 M

Therefore, the concentration of CdS1U1P12+S1S1P0(aq) in the mixture is 1.34 × 10S1U1P1-5S1S1P0 M, which is closest to choice C (1.8 × 10S1U1P1-9S1S1P0 M).

Quiz 18: Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

If 500 mL of 1.4 × 10^-6 M AgNO₃ is mixed with 500 mL of 1.4 × 10^-6 M NaBr, what will occur? For AgBr, K_sp = 5 × 10^-13.

What is the minimum mass of Na₂CO₃ (molar mass = 105.990 g/mol) that must be added to 43.4 mL of a 1.0 × 10^-4 M AgNO₃ solution in order for precipitation to occur? The K_sp of Ag₂CO₃ is 8.6 × 10^-12. Assume no volume change occurs upon addition of Na₂CO₃.

What is the minimum concentration of Cd²⁺ required to begin precipitating Cd(OH) ₂(s) in a solution buffered at pH 10.83? The K_sp of Cd(OH) ₂ is 5.3 × 10^-15 and K_w = 1.01 × 10^-14.

Calculate the molar concentration of uncomplexed Zn²⁺(aq) in a solution that contains 0.17 M Zn(NH₃) ₄²⁺ and 0.3775 M NH₃ at equilibrium. K_f for Zn(NH₃) ₄²⁺ is $2.9 \times 10 ^ { 9 }$ .

In which of the following solutions would silver(I) phosphate, Ag₃PO₄, be least soluble?

Two important biological buffer systems control pH in the range of 6.9 to 7.4. These buffer systems are H₂CO₃/HCO₃^- and _____.

What is the maximum hydroxide-ion concentration that a 0.019 M MgCl₂ solution could have without causing the precipitation of Mg(OH) ₂? For Mg(OH) ₂, K_sp = 1.8 × 10^-11.

What is the molar solubility of solid iron(III) hydroxide, Fe(OH) ₃, in a solution that is buffered to a pH of 2.50 at 25 °C? The K_sp of Fe(OH) ₃ is 6.3 × 10^-38 at 25 °C.

A 5.0 × 10^-4 M solution of MnSO₄ is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? The K_sp of Mn(OH) ₂ is 2.0 × 10^-13 and K_w = 1.01 × 10^-14.

Suppose 50.00 mL of 2.0 × 10^-5 M Fe(NO₃) ₃ is added to 50.00 mL of 2.0 ×10^-4 M KIO₃. Which of the following statements is true? For Fe(IO₃) ₃, K_sp = 1.0 × 10^-14.

What is the molar solubility of Mn(OH) ₂(s) in a solution that is buffered at pH 8.00 at 25 °C? The K_sp of Mn(OH) ₂ is 1.9 × 10^-13 at 25 °C.

What is the value of the dissociation constant, K_dissociation, for the complex ion Zn(NH₃) ₄²⁺? (K_f = 2.9 × 10⁹)

The concentration of Pb²⁺ in an aqueous solution is 5.5 × 10^-3 M. What concentration of SO₄^2- is required to begin precipitating PbSO₄? The K_sp of PbSO₄ is 2.5 × 10^-8.

What is the concentration of Cd²⁺(aq) in a mixture of 0.014 mol Cd(NO₃) ₂ and 1.0 mol NH₃ diluted to 1.00 L? For Cd(NH₃) ₄²⁺, K_f = 1.0 × 10⁷.

Quiz 18: Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

If 500 mL of 1.4 × 10-6 M AgNO3 is mixed with 500 mL of 1.4 × 10-6 M NaBr, what will occur? For AgBr, Ksp = 5 × 10-13.

What is the minimum mass of Na2CO3 (molar mass = 105.990 g/mol) that must be added to 43.4 mL of a 1.0 × 10-4 M AgNO3 solution in order for precipitation to occur? The Ksp of Ag2CO3 is 8.6 × 10-12. Assume no volume change occurs upon addition of Na2CO3.

What is the minimum concentration of Cd2+ required to begin precipitating Cd(OH) 2(s) in a solution buffered at pH 10.83? The Ksp of Cd(OH) 2 is 5.3 × 10-15 and Kw = 1.01 × 10-14.

Calculate the molar concentration of uncomplexed Zn2+(aq) in a solution that contains 0.17 M Zn(NH3) 42+ and 0.3775 M NH3 at equilibrium. Kf for Zn(NH3) 42+ is 2.9×1092.9 \times 10 ^ { 9 }2.9×109 .

In which of the following solutions would silver(I) phosphate, Ag3PO4, be least soluble?

Consider the reaction Cu2+(aq) + 4 NH3(aq) ⇋\leftrightharpoons⇋ Cu(NH3) 42+(aq) Kf = 2.1 × 1013 If the Ksp for Cu(OH) 2 is 2.2 × 10-20, what is the value of the equilibrium constant, K, for the reaction below? Cu(NH3) 42+(aq) + 2 OH-(aq) ⇋\leftrightharpoons⇋ Cu(OH) 2(s) + 4 NH3(aq)

An aqueous solution contains 0.010 M bromide ion (Br-) and 0.010 M iodide ion (I-) . If silver ions (Ag+) are added to the solution until silver bromide just begins to precipitate, what are the concentrations of silver ions and iodide ions? (Ksp of AgBr = 5.4 × 10-13 and Ksp of AgI = 8.5 × 10-17)

Two important biological buffer systems control pH in the range of 6.9 to 7.4. These buffer systems are H2CO3/HCO3- and _____.

What is the maximum hydroxide-ion concentration that a 0.019 M MgCl2 solution could have without causing the precipitation of Mg(OH) 2? For Mg(OH) 2, Ksp = 1.8 × 10-11.

What is the molar solubility of solid iron(III) hydroxide, Fe(OH) 3, in a solution that is buffered to a pH of 2.50 at 25 °C? The Ksp of Fe(OH) 3 is 6.3 × 10-38 at 25 °C.

A 5.0 × 10-4 M solution of MnSO4 is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? The Ksp of Mn(OH) 2 is 2.0 × 10-13 and Kw = 1.01 × 10-14.

Suppose 50.00 mL of 2.0 × 10-5 M Fe(NO3) 3 is added to 50.00 mL of 2.0 ×10-4 M KIO3. Which of the following statements is true? For Fe(IO3) 3, Ksp = 1.0 × 10-14.

What is the molar solubility of Mn(OH) 2(s) in a solution that is buffered at pH 8.00 at 25 °C? The Ksp of Mn(OH) 2 is 1.9 × 10-13 at 25 °C.

What is the value of the dissociation constant, Kdissociation, for the complex ion Zn(NH3) 42+? (Kf = 2.9 × 109)

The concentration of Pb2+ in an aqueous solution is 5.5 × 10-3 M. What concentration of SO42- is required to begin precipitating PbSO4? The Ksp of PbSO4 is 2.5 × 10-8.

What is the concentration of Cd2+(aq) in a mixture of 0.014 mol Cd(NO3) 2 and 1.0 mol NH3 diluted to 1.00 L? For Cd(NH3) 42+, Kf = 1.0 × 107.​

If 500 mL of 1.4 × 10^-6 M AgNO₃ is mixed with 500 mL of 1.4 × 10^-6 M NaBr, what will occur? For AgBr, K_sp = 5 × 10^-13.

What is the minimum mass of Na₂CO₃ (molar mass = 105.990 g/mol) that must be added to 43.4 mL of a 1.0 × 10^-4 M AgNO₃ solution in order for precipitation to occur? The K_sp of Ag₂CO₃ is 8.6 × 10^-12. Assume no volume change occurs upon addition of Na₂CO₃.

What is the minimum concentration of Cd²⁺ required to begin precipitating Cd(OH) ₂(s) in a solution buffered at pH 10.83? The K_sp of Cd(OH) ₂ is 5.3 × 10^-15 and K_w = 1.01 × 10^-14.

Calculate the molar concentration of uncomplexed Zn²⁺(aq) in a solution that contains 0.17 M Zn(NH₃) ₄²⁺ and 0.3775 M NH₃ at equilibrium. K_f for Zn(NH₃) ₄²⁺ is $2.9 \times 10 ^ { 9 }$ .

In which of the following solutions would silver(I) phosphate, Ag₃PO₄, be least soluble?

Two important biological buffer systems control pH in the range of 6.9 to 7.4. These buffer systems are H₂CO₃/HCO₃^- and _____.

What is the maximum hydroxide-ion concentration that a 0.019 M MgCl₂ solution could have without causing the precipitation of Mg(OH) ₂? For Mg(OH) ₂, K_sp = 1.8 × 10^-11.

What is the molar solubility of solid iron(III) hydroxide, Fe(OH) ₃, in a solution that is buffered to a pH of 2.50 at 25 °C? The K_sp of Fe(OH) ₃ is 6.3 × 10^-38 at 25 °C.

A 5.0 × 10^-4 M solution of MnSO₄ is gradually made more basic by adding NaOH. At what pH will manganese(II) hydroxide begin to precipitate? The K_sp of Mn(OH) ₂ is 2.0 × 10^-13 and K_w = 1.01 × 10^-14.

Suppose 50.00 mL of 2.0 × 10^-5 M Fe(NO₃) ₃ is added to 50.00 mL of 2.0 ×10^-4 M KIO₃. Which of the following statements is true? For Fe(IO₃) ₃, K_sp = 1.0 × 10^-14.

What is the molar solubility of Mn(OH) ₂(s) in a solution that is buffered at pH 8.00 at 25 °C? The K_sp of Mn(OH) ₂ is 1.9 × 10^-13 at 25 °C.

What is the value of the dissociation constant, K_dissociation, for the complex ion Zn(NH₃) ₄²⁺? (K_f = 2.9 × 10⁹)

The concentration of Pb²⁺ in an aqueous solution is 5.5 × 10^-3 M. What concentration of SO₄^2- is required to begin precipitating PbSO₄? The K_sp of PbSO₄ is 2.5 × 10^-8.

What is the concentration of Cd²⁺(aq) in a mixture of 0.014 mol Cd(NO₃) ₂ and 1.0 mol NH₃ diluted to 1.00 L? For Cd(NH₃) ₄²⁺, K_f = 1.0 × 10⁷.