Question 1

Consider the following table of KS1U1B1sp S1U1B0values. 
-Which compound listed below has the smallest molar solubility in water?

Accepted Answer

AgI has the smallest molar solubility in water based on the solubility rules. It is a sparingly soluble salt and forms a precipitate when mixed with water. The other compounds listed are either soluble or more soluble in water than AgI.

Question 2

Of the following solutions, which has the greatest buffering capacity?

Accepted Answer

Buffer capacity is directly proportional to the concentration of the buffer components. In this case, the concentration of both HF and NaF is highest in option B, making it the buffer with the greatest buffering capacity.

Question 3

The primary buffer system that controls the pH of the blood is the _ _ buffer system.

Accepted Answer

The carbonic acid-bicarbonate buffer system is the primary buffer system that controls the pH of the blood. It involves the reversible reaction of carbonic acid (H2CO3) and bicarbonate (HCO3-) which can regulate the concentration of hydrogen ions (H+) and therefore, the pH of the blood.

Question 4

Which one of the following pairs cannot be mixed together to form a buffer solution?

Accepted Answer

The answer of Which one of the following pairs cannot...

Question 5

A 25.0- mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The K_aof butanoic acid is 1.5 × 10^-⁵.

Accepted Answer

The initial pH of a solution of a weak acid can be calculated using the equation:
pH = pKa + log([A-]/[HA])
where pKa is the acid dissociation constant, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the acid.
For butanoic acid, the pKa is 4.82.
Using the given concentration and volume of the acid, we can calculate the number of moles of butanoic acid present in the solution:
0.150 mol/L × 0.025 L = 0.00375 mol
Since the acid and base are both 0.150 M, we know that the volume of NaOH added to reach the equivalence point will also be 25.0 mL.
At the equivalence point, all of the butanoic acid will have reacted with the NaOH to form butanoate ions and water:
CH3CH2CH2COOH + NaOH → CH3CH2CH2COO- + H2O
The number of moles of NaOH required to reach the equivalence point is:
0.150 mol/L × 0.025 L = 0.00375 mol
Since the moles of butanoic acid and NaOH are equal at the equivalence point, we know that the initial concentration of butanoate ions before any base is added is also 0.150 M. Therefore, the initial concentration of butanoic acid is also 0.150 M, since the acid and its conjugate base are in equilibrium.
Plugging in the values into the equation for pH, we get:
pH = 4.82 + log([0.150]/[0.150])
pH = 4.82
Therefore, the initial pH before any base is added is 4.82. The correct answer is D, 2.83.

Question 6

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO₂) and 0.278 M in potassium nitrite (KNO₂). The acid dissociation constant of nitrous acid is 4)50 × 10^-⁴.

Accepted Answer

The equation for the dissociation of nitrous acid is: HNO₂(aq) ↔ H+ (aq) + NO₂-(aq) The acid dissociation constant (Ka) is: Ka = [H+][NO₂-]/[HNO₂] We are given the concentration of nitrous acid (HNO₂) and potassium nitrite (KNO₂) in the solution. Since nitrous acid is a weak acid, we can assume that the concentration of H+ ions from the dissociation of water is negligible compared to that from the dissociation of nitrous acid. Therefore, we can assume that [H+] ≈ [NO₂-]. Let x be the percent ionization of nitrous acid. Then: Ka = x^2/(0.222 - x) Substituting the given Ka value and solving for x: 4.50 × 10^-⁴ = x^2/(0.222 - x) x = 0.161 or 16.1% Therefore, the percent ionization of nitrous acid in the solution is 16.1%. Thus, the best choice is C.

Question 7

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10^-⁴.

Accepted Answer

The answer of Calculate the percent ionization of nitrous acid...

Question 8

In which of the following aqueous solutions would you expect AgCl to have the highest solubility?

Accepted Answer

AgCl is insoluble in water and its solubility is very low. Therefore, in all of the given solutions, AgCl will have very low solubility. However, in pure water, there are no other ions present to compete with Ag+ and Cl- for occupying the limited space available for the dissolution of AgCl. Therefore, the solubility of AgCl will be the highest in pure water.

Question 9

A 25.0 mL sample of a solution of a monoprotic acid is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The concentration of the monoprotic acid is about mol/L.

Accepted Answer

The equivalence point on the titration curve indicates that the moles of acid equal the moles of base added. Using the volume of NaOH at the equivalence point and its concentration, the concentration of the acid can be calculated.

Question 10

A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba²⁺. When the concentration of F^-exceeds M, BaF₂will precipitate. Neglect volume changes. For BaF₂, K_sp= 1.7 × 10^-⁶.

Accepted Answer

To find the concentration of F⁻ needed to precipitate BaF₂, use the Ksp expression: Ksp = [Ba²⁺][F⁻]². Given Ksp = 1.7 × 10⁻⁶ and [Ba²⁺] = 0.0144 M, solve for [F⁻]: 1.7 × 10⁻⁶ = 0.0144 × [F⁻]². [F⁻]² = 1.7 × 10⁻⁶ / 0.0144, [F⁻] = √(1.7 × 10⁻⁶ / 0.0144) ≈ 0.011 M or 1.1 × 10⁻² M.

Question 11

What are the principal organs that regulate the pH of the carbonic acid- bicarbonate buffer system in the blood?

Accepted Answer

The lungs and kidneys are the two principal organs that regulate the pH of the carbonic acid-bicarbonate buffer system in the blood. The lungs regulate the amount of CO2 in the blood, which affects the balance between carbonic acid and bicarbonate ions. The kidneys regulate the amount of bicarbonate ions in the blood by either excreting or reabsorbing them.

Question 12

What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?

Accepted Answer

When HCl is added, it will react with the hydrogen fluoride present in the solution to form more fluoride ions and water. This will cause a decrease in the concentration of fluoride ion and an increase in the concentration of hydrogen fluoride. The balanced equation for the reaction is: HF + HCl → H2O + F- + Cl-

Question 13

Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO₂) and 0.205 M in formic acid (HCO₂H). The K_aof formic acid is 1.77 × 10^-⁴.

Accepted Answer

Formic acid is a weak acid, and when it is dissolved in water, it partially dissociates to give formate ions and hydronium ions. The balanced equation for this dissociation reaction is: HCO₂H + H2O ⇌ H3O+ + CO₂ The acid dissociation constant (Ka) for this reaction can be used to calculate the pH of the solution using the following formula: pH = -log[H3O+] Ka for formic acid is given as 1.77 × 10^-⁴. We can use this value to calculate the concentration of hydronium ions in the solution, which is necessary for finding the pH. The Ka expression is: Ka = [H3O+][CO₂-]/[HCO₂H] At equilibrium, the concentrations of formate and hydronium ions are equal to each other, i.e. [CO₂-] = [H3O+]. If x is the concentration of hydronium ions that result from the dissociation of formic acid, then the concentrations of formic acid and formate ions can be expressed as (0.205 - x) and (0.295 + x), respectively. Plugging these concentrations into the Ka expression and solving for x, we get: 1.77 × 10^-⁴ = x^2/(0.205 - x) x = 0.0136 M (to 3 significant figures) Therefore, the pH of the solution is: pH = -log(0.0136) = 3.903

Question 14

Why does fluoride treatment render teeth more resistant to decay?

Accepted Answer

Fluoride treatment converts the hydroxyapatite crystals in tooth enamel to fluoroapatite, a more acid-resistant compound, making teeth more resistant to decay.

Question 15

Consider the following table of KS1U1B1sp S1U1B0values. 
-Which compound listed below has the greatest molar solubility in water?

Accepted Answer

CaF₂ has a higher molar solubility in water compared to the other compounds listed, which are generally less soluble due to their lower solubility product constants (Ksp).

Question 16

Which one of the following will cause hemoglobin to release oxygen?

Accepted Answer

Decrease in pH (acidosis) will cause hemoglobin to release oxygen to tissues in need of oxygen. This is known as the Bohr effect.

Question 17

In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?

Accepted Answer

The answer of In which of the following aqueous solutions...

Question 18

Human blood is .

Accepted Answer

Human blood is slightly basic, with a normal pH range of about 7.35 to 7.45.

Question 19

A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The unknown compound is .

Accepted Answer

The titration curve shows a gradual increase in pH from 2 to 8, indicating that the unknown compound is an acid. The steep rise in pH near the equivalence point suggests that the acid is a weak acid, as the addition of a small amount of NaOH caused a large increase in pH. Therefore, the best choice is C, a weak acid.

Question 20

What is the molar solubility of magnesium carbonate ( MgCO₃) in water? The solubility- product constant for MgCO₃is 3.5 × 10^-⁸at 25°C.

Accepted Answer

The molar solubility (s) of MgCO3 can be calculated using the formula Ksp = s^2 for a salt that dissociates into two ions. Solving s^2 = 3.5 × 10^-8 gives s = 1.9 × 10^-4.

Quiz 17: Additional Aspects of Equilibria

Consider the following table of K_spvalues. -Which compound listed below has the smallest molar solubility in water?

Of the following solutions, which has the greatest buffering capacity?

The primary buffer system that controls the pH of the blood is the _ _ buffer system.

Which one of the following pairs cannot be mixed together to form a buffer solution?

A 25.0- mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The K_aof butanoic acid is 1.5 × 10^-⁵.

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO₂) and 0.278 M in potassium nitrite (KNO₂) . The acid dissociation constant of nitrous acid is 4) 50 × 10^-⁴.

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10^-⁴.

In which of the following aqueous solutions would you expect AgCl to have the highest solubility?

A 25.0 mL sample of a solution of a monoprotic acid is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The concentration of the monoprotic acid is about mol/L.

A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba²⁺. When the concentration of F^-exceeds M, BaF₂will precipitate. Neglect volume changes. For BaF₂, K_sp= 1.7 × 10^-⁶.

What are the principal organs that regulate the pH of the carbonic acid- bicarbonate buffer system in the blood?

What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?

Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO₂) and 0.205 M in formic acid (HCO₂H) . The K_aof formic acid is 1.77 × 10^-⁴.

Why does fluoride treatment render teeth more resistant to decay?

Consider the following table of K_spvalues. -Which compound listed below has the greatest molar solubility in water?

Which one of the following will cause hemoglobin to release oxygen?

In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?

Human blood is .

A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The unknown compound is .

What is the molar solubility of magnesium carbonate ( MgCO₃) in water? The solubility- product constant for MgCO₃is 3.5 × 10^-⁸at 25°C.

Quiz 17: Additional Aspects of Equilibria

Consider the following table of Ksp values. -Which compound listed below has the smallest molar solubility in water?

Of the following solutions, which has the greatest buffering capacity?

The primary buffer system that controls the pH of the blood is the _ _ buffer system.

Which one of the following pairs cannot be mixed together to form a buffer solution?

A 25.0- mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The Ka of butanoic acid is 1.5 × 10- 5.

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO2) and 0.278 M in potassium nitrite (KNO2) . The acid dissociation constant of nitrous acid is 4) 50 × 10- 4.

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10- 4.

In which of the following aqueous solutions would you expect AgCl to have the highest solubility?

A 25.0 mL sample of a solution of a monoprotic acid is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The concentration of the monoprotic acid is about mol/L.

A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba2+. When the concentration of F- exceeds M, BaF2 will precipitate. Neglect volume changes. For BaF2, Ksp = 1.7 × 10- 6.

What are the principal organs that regulate the pH of the carbonic acid- bicarbonate buffer system in the blood?

What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?

Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO2) and 0.205 M in formic acid (HCO2H) . The Ka of formic acid is 1.77 × 10- 4.

Why does fluoride treatment render teeth more resistant to decay?

Consider the following table of Ksp values. -Which compound listed below has the greatest molar solubility in water?

Which one of the following will cause hemoglobin to release oxygen?

In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?

Human blood is .

A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The unknown compound is .

What is the molar solubility of magnesium carbonate ( MgCO3 ) in water? The solubility- product constant for MgCO3 is 3.5 × 10- 8 at 25°C.

Consider the following table of K_spvalues. -Which compound listed below has the smallest molar solubility in water?

A 25.0- mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The K_aof butanoic acid is 1.5 × 10^-⁵.

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO₂) and 0.278 M in potassium nitrite (KNO₂) . The acid dissociation constant of nitrous acid is 4) 50 × 10^-⁴.

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10^-⁴.

A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba²⁺. When the concentration of F^-exceeds M, BaF₂will precipitate. Neglect volume changes. For BaF₂, K_sp= 1.7 × 10^-⁶.

Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO₂) and 0.205 M in formic acid (HCO₂H) . The K_aof formic acid is 1.77 × 10^-⁴.

Consider the following table of K_spvalues. -Which compound listed below has the greatest molar solubility in water?

What is the molar solubility of magnesium carbonate ( MgCO₃) in water? The solubility- product constant for MgCO₃is 3.5 × 10^-⁸at 25°C.