Question 1

How many moles of KOH(s)must be added to 1.00 L of 0.782 M HF(aq)to produce a buffer with a pH = 4.00?

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Question 2

In the titration of 0.300 M CH₃NH₂(aq)with 0.300 M HCl(aq),what is the formula of the major species and what is its concentration at the equivalence point?

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Question 3

The solubility of all except which the following compounds increases as the pH of the solution decreases?

Accepted Answer

The solubility of compounds like CaF2, Na2CO3, PbSO4, and CuS increases as the pH of the solution decreases because these compounds form weak acids or react with H+ ions, which helps dissolve the compound. However, KClO4 is a strong electrolyte that dissolves in water regardless of the pH, so its solubility is not affected by changes in pH.

Question 4

The solubility of silver bromide is greater in 0.10 M NaBr than in pure water.True or false?

Accepted Answer

The solubility of silver bromide decreases in 0.10 M NaBr solution compared to pure water due to the common ion effect, where the presence of bromide ions from NaBr reduces the solubility of AgBr.

Question 5

If 10.0 mmol of sodium hydroxide is added to 1.00 L of a buffer that is 0.200 M HClO(aq)and 0.155 M NaHClO(aq),the final concentrations of HClO(aq)and ClO ^- (aq),respectively,are

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Question 6

When silver ions form a coordination complex with the thiosulfate ion,the latter acts as a Lewis acid.True or false?

Accepted Answer

In the coordination complex, the thiosulfate ion acts as a Lewis base because it donates a pair of electrons to the silver ion, which is the Lewis acid.

Question 7

The solubility of silver chloride is greater in 0.01 M NH₃(aq)because of formation of the coordination complex Ag(NH₃)₂⁺(aq).True or false?

Accepted Answer

The coordination complex Ag(NH₃)₂⁺(aq) forms due to the interaction of silver ions with the ligand NH₃ in the solution. This complex is more soluble in water than the silver chloride, leading to the greater solubility of silver chloride in the presence of NH₃(aq).

Question 8

The weak base,B,has K_b = 3.1 × 10 ^- ⁴.The pH of a solution in which [B] = [BH⁺] is

Accepted Answer

The equation for the dissociation of the weak base, B, can be written as:

B + H2O ⇌ BH+ + OH-

The dissociation constant, Kb, for this reaction can be found using the equation:

Kb = Kw/Ka

Where Kw is the ion product constant (1.0 x 10^-14) and Ka is the acid dissociation constant for the conjugate acid of the weak base (BH+ in this case). Since BH+ is not given, we can assume it has a negligible acid dissociation constant, and therefore Kb ≈ Kw/[BHS1U1P1].

Using the given equilibrium constant, KS1U1B1bS1U1B0, we can write:

KS1U1B1bS1U1B0 = [BH+][OH-]/[B]

At equilibrium, [BH+] = [OH-], so we can substitute [BH+] for [OH-] and rearrange to solve for [BH+]/[B]:

[BH+]/[B] = √(KS1U1B1bS1U1B0)

Since [B] = [B] + [BH+], we can use the ratio [BH+]/[B] to find [B] and [BH+], and use these values to find the pH of the solution.

Let x = [BH+]/[B]. Then:

[B] = [BHS1U1P1+] + [BH+] = [B](1 + x)

Solving for [B], we get:

[B] = [BHS1U1P1+]/(1 - x)

Substituting this into the equilibrium constant expression and simplifying, we get:

KS1U1B1bS1U1B0 = x^2/(1 - x)

Rearranging and solving for x using the quadratic formula, we get:

x = (√(4KS1U1B1bS1U1B0 + 1) - 1)/2

Plugging in the given value for KS1U1B1bS1U1B0, we get:

x = 0.995

Therefore, [B] = 1 - x = 0.005, and [BH+] = x[B] = 0.004975.

To find the pH, we can use the equation:

pH = pKa + log([A-]/[HA])

Where A- is the conjugate base of the acid, HA, and pKa is the acid dissociation constant for HA. In this case, BH+ is the acid and B is the conjugate base, so:

pH = 14 - pKb + log([B]/[BH+])

Substituting in our values, we get:

pH = 14 - 4.51 + log(0.005/0.004975)

pH ≈ 10.49

Question 9

In the titration of 0.300 M H₃PO₄(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

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Question 10

The K_spfor mercury(I)iodide is 1.2 *10 ^- ²⁸.What is the solubility of mercury(I)iodide?

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Question 11

What is the equilibrium constant for the reaction HCN(aq)+ OH^-(aq) CN^-(aq)+ H₂O(l)

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Question 12

Assuming no volume change on mixing,what mass of ammonium chloride should be added to 1.00 L of 0.250 M NH₃(aq)to produce a buffer of pH 10.10? The molar mass of ammonium chloride is 53.49 g/mol.

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Question 13

You have available the following reagents as 0.10 M aqueous solutions: NaOH,HCl,phenol (pK_a = 9.89),aniline (pK_b = 9.37),HNO₂ (pK_a = 3.37),CH₃NH₂ (pK_b = 3.44).Which two reagents would you use to make a buffer with a pH of 10.5?

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Question 14

If 50.0 mL of 0.22 M NaCl(aq)is mixed with 50.0 mL of 0.0050 M AgNO₃(aq),will AgCl(s)precipitate? K_sp(AgCl)= 1.6 × 10 ^- ¹⁰.

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Quiz 13: Aqueous Equilibria

How many moles of KOH(s)must be added to 1.00 L of 0.782 M HF(aq)to produce a buffer with a pH = 4.00?

In the titration of 0.300 M CH₃NH₂(aq)with 0.300 M HCl(aq),what is the formula of the major species and what is its concentration at the equivalence point?

The solubility of all except which the following compounds increases as the pH of the solution decreases?

The solubility of silver bromide is greater in 0.10 M NaBr than in pure water.True or false?

If 10.0 mmol of sodium hydroxide is added to 1.00 L of a buffer that is 0.200 M HClO(aq) and 0.155 M NaHClO(aq) ,the final concentrations of HClO(aq) and ClO ^- (aq) ,respectively,are

When silver ions form a coordination complex with the thiosulfate ion,the latter acts as a Lewis acid.True or false?

The solubility of silver chloride is greater in 0.01 M NH₃(aq)because of formation of the coordination complex Ag(NH₃)₂⁺(aq).True or false?

The weak base,B,has K_b = 3.1 × 10 ^- ⁴.The pH of a solution in which [B] = [BH⁺] is

In the titration of 0.300 M H₃PO₄(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

The K_spfor mercury(I) iodide is 1.2 *10 ^- ²⁸.What is the solubility of mercury(I) iodide?

What is the equilibrium constant for the reaction HCN(aq) + OH^-(aq) CN^-(aq) + H₂O(l)

Assuming no volume change on mixing,what mass of ammonium chloride should be added to 1.00 L of 0.250 M NH₃(aq)to produce a buffer of pH 10.10? The molar mass of ammonium chloride is 53.49 g/mol.

You have available the following reagents as 0.10 M aqueous solutions: NaOH,HCl,phenol (pK_a = 9.89) ,aniline (pK_b = 9.37) ,HNO₂ (pK_a = 3.37) ,CH₃NH₂ (pK_b = 3.44) .Which two reagents would you use to make a buffer with a pH of 10.5?

If 50.0 mL of 0.22 M NaCl(aq)is mixed with 50.0 mL of 0.0050 M AgNO₃(aq),will AgCl(s)precipitate? K_sp(AgCl)= 1.6 × 10 ^- ¹⁰.

Quiz 13: Aqueous Equilibria

How many moles of KOH(s)must be added to 1.00 L of 0.782 M HF(aq)to produce a buffer with a pH = 4.00?

In the titration of 0.300 M CH3NH2(aq)with 0.300 M HCl(aq),what is the formula of the major species and what is its concentration at the equivalence point?

The solubility of all except which the following compounds increases as the pH of the solution decreases?

The solubility of silver bromide is greater in 0.10 M NaBr than in pure water.True or false?

If 10.0 mmol of sodium hydroxide is added to 1.00 L of a buffer that is 0.200 M HClO(aq) and 0.155 M NaHClO(aq) ,the final concentrations of HClO(aq) and ClO - (aq) ,respectively,are

When silver ions form a coordination complex with the thiosulfate ion,the latter acts as a Lewis acid.True or false?

The solubility of silver chloride is greater in 0.01 M NH3(aq)because of formation of the coordination complex Ag(NH3)2+(aq).True or false?

The weak base,B,has Kb = 3.1 × 10 - 4.The pH of a solution in which [B] = [BH+] is

In the titration of 0.300 M H3PO4(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

The Ksp for mercury(I) iodide is 1.2 *10 - 28.What is the solubility of mercury(I) iodide?

What is the equilibrium constant for the reaction HCN(aq) + OH-(aq) CN-(aq) + H2O(l)

Assuming no volume change on mixing,what mass of ammonium chloride should be added to 1.00 L of 0.250 M NH3(aq)to produce a buffer of pH 10.10? The molar mass of ammonium chloride is 53.49 g/mol.

You have available the following reagents as 0.10 M aqueous solutions: NaOH,HCl,phenol (pKa = 9.89) ,aniline (pKb = 9.37) ,HNO2 (pKa = 3.37) ,CH3NH2 (pKb = 3.44) .Which two reagents would you use to make a buffer with a pH of 10.5?

If 50.0 mL of 0.22 M NaCl(aq)is mixed with 50.0 mL of 0.0050 M AgNO3(aq),will AgCl(s)precipitate? Ksp(AgCl)= 1.6 × 10 - 10.

In the titration of 0.300 M CH₃NH₂(aq)with 0.300 M HCl(aq),what is the formula of the major species and what is its concentration at the equivalence point?

If 10.0 mmol of sodium hydroxide is added to 1.00 L of a buffer that is 0.200 M HClO(aq) and 0.155 M NaHClO(aq) ,the final concentrations of HClO(aq) and ClO ^- (aq) ,respectively,are

The solubility of silver chloride is greater in 0.01 M NH₃(aq)because of formation of the coordination complex Ag(NH₃)₂⁺(aq).True or false?

The weak base,B,has K_b = 3.1 × 10 ^- ⁴.The pH of a solution in which [B] = [BH⁺] is

In the titration of 0.300 M H₃PO₄(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

The K_spfor mercury(I) iodide is 1.2 *10 ^- ²⁸.What is the solubility of mercury(I) iodide?

What is the equilibrium constant for the reaction HCN(aq) + OH^-(aq) CN^-(aq) + H₂O(l)

Assuming no volume change on mixing,what mass of ammonium chloride should be added to 1.00 L of 0.250 M NH₃(aq)to produce a buffer of pH 10.10? The molar mass of ammonium chloride is 53.49 g/mol.

You have available the following reagents as 0.10 M aqueous solutions: NaOH,HCl,phenol (pK_a = 9.89) ,aniline (pK_b = 9.37) ,HNO₂ (pK_a = 3.37) ,CH₃NH₂ (pK_b = 3.44) .Which two reagents would you use to make a buffer with a pH of 10.5?

If 50.0 mL of 0.22 M NaCl(aq)is mixed with 50.0 mL of 0.0050 M AgNO₃(aq),will AgCl(s)precipitate? K_sp(AgCl)= 1.6 × 10 ^- ¹⁰.