Question 1

The following is an accurate description of the ionization of HBr in water.

Accepted Answer

False

Question 2

Both the kidneys and the carbon dioxide-carbonic acid cycle help regulate blood pH.

Accepted Answer

Both the kidneys and the carbon dioxide-carbonic acid cycle play important roles in maintaining a normal blood pH level. The kidneys regulate pH by excreting or retaining acidic or basic substances, while the carbon dioxide-carbonic acid cycle helps regulate pH levels by controlling the concentration of carbonic acid in the blood.

Question 3

H⁺, H₃O⁺, and OH⁺ are different ways of representing the species that causes a solution to be acidic.

Accepted Answer

The given representations seem to be a mix of symbols and numbers that do not correspond to any recognized chemical notation for acids or other species that cause solutions to be acidic. Chemical species that cause solutions to be acidic are typically represented by their chemical formulas, such as HCl for hydrochloric acid, H2SO4 for sulfuric acid, etc.

Question 4

The following solutions are ranked from the most acidic to the most basic. Most acidic urine (pH 5.89) intestine contents (pH 8.06) blood (pH 7.30) Most basic

Accepted Answer

The correct order from most acidic to most basic should be: urine (pH 5.89), blood (pH 7.30), intestine contents (pH 8.06).

Question 5

For a healthy individual, the pH of the blood in the veins is lower than in the arteries.

Accepted Answer

The pH of blood in the veins and arteries is similar, with a slightly higher pH in the arteries. In healthy individuals, the pH of arterial blood typically ranges from 7.35-7.45 and the pH of venous blood ranges from 7.31-7.41.

Question 6

Very rapid breathing can lead to a condition know as respiratory acidosis.

Accepted Answer

Very rapid breathing leads to respiratory alkalosis, not acidosis, because it causes excessive expulsion of CO2, which decreases the acidity of the blood.

Question 7

Adipic acid has the formula given below.  This is a polyprotic acid.

Accepted Answer

Adipic acid has two acidic hydrogen atoms and can donate two protons in solution, making it a polyprotic acid.

Question 8

A solution composed of HCl and NaCl would produce an effective buffer.

Accepted Answer

A buffer solution must have both a weak acid and its conjugate base, or a weak base and its conjugate acid, in order to effectively resist changes in pH. HCl is a strong acid and does not have a conjugate base, while NaCl is a salt and does not contain any acidic or basic components. Therefore, a solution composed of HCl and NaCl would not produce an effective buffer.

Question 9

Which of the following is present in pure water? A) H₃O⁺ B) OH− C) H₂O D) All are present in pure water.

Accepted Answer

Pure water naturally contains H3O+ (hydronium ions), OH− (hydroxide ions), and H2O molecules. These species are in equilibrium with each other, which is a fundamental concept in the chemistry of water.

Question 10

The following represents the structure of a hydronium ion.

Accepted Answer

The given structure is not provided in the format required to be identified and confirmed as a hydronium ion.

Question 11

A solution is 0.10 M in ascorbic acid (Vitamin C), H₂C₆H₆O₆, and 0.10 M in sodium ascorbate, NaHC₆H₆O₆. When base is added to the solution, H₂C₆H₆O₆ neutralizes the added base.

Accepted Answer

The presence of the conjugate base, H₂C₆H₆O₆, in the solution indicates that ascorbic acid has acted as an acid and donated a proton to form this conjugate base. Therefore, when a base is added to the solution, this conjugate base can react with the added base and neutralize it.

Question 12

The molar concentration of H₃O⁺ in an aqueous solution would be increased by the addition of KOH.

Accepted Answer

The addition of KOH would not increase the molar concentration of H₃O⁺, as it is not an acid-base reaction involving this species.

Question 13

Adipic acid has the formula given below.  Thus substance would be classified as amphiprotic.

Accepted Answer

Adipic acid is a dicarboxylic acid and can donate two protons (H+) but cannot accept them. Therefore, it is not amphiprotic.

Question 14

An aqueous solution contains a [H₃O⁺] that is 1.0 × 10^-3 M. What is the [OH^-] of this solution? A) 1.0 × 10^-14 M B) 1.0 × 10^-11 M C) 1.0 × 10^-3 M D) 1.0 × 10¹¹ M

Accepted Answer

The equation for the dissociation of H2SO4 is:

H2SO4 ↔ H+ + HSO4-

The acid dissociation constant (Ka) for H2SO4 is 1.0 × 10^-2.

The equation for the dissociation of HSO4- is:

HSO4- ↔ H+ + SO42-

The acid dissociation constant (Ka) for HSO4- is 1.0 × 10^-2.

We are given the concentration of the HSO4- ion, which is the conjugate base of the H2SO4 acid. To find the concentration [H+] of the acid, we can use the acid dissociation constant and the concentration of the conjugate base:

Ka = [H+][HSO4-]/[H2SO4]

[H+] = Ka[H2SO4]/[HSO4-]

[H+] = (1.0 × 10^-2)(1.0 × 10^-2)/1.0 × 10^-3

[H+] = 1.0 × 10^-1

The pH of the solution is the negative logarithm of the hydrogen ion concentration:

pH = -log[H+]

pH = -log(1.0 × 10^-1)

pH = 1

Therefore, the pH of the solution is 1 or B.

Question 15

Nitroaniline (C₆H₆N₂O₂) is a weak base. This would indicate that the pH of a 0.010 M solution of nitroaniline will be less than 7.

Accepted Answer

The answer of Nitroaniline (C₆H₆N₂O₂) is a weak base. This...

Question 16

The pK_a of lactic acid is 3.86, an equimolar solution of lactic acid and potassium lactate will have a pH of 7.72.

Accepted Answer

The correct value of pK_a for lactic acid is 3.86, which means that at pH 3.86, half of the lactic acid molecules will be dissociated into lactate and hydrogen ions. At pH 7.72, most of the lactic acid will be in the form of lactate ions, but not necessarily in an equimolar mixture with lactic acid. Therefore, the statement is false.

Question 17

The range of breaths per minute, also known as respiratory rate, for a normal, healthy adult is 12-20 breaths per minute. A breathing rate of higher than this is termed hyperventilation.

Accepted Answer

This statement is true.

Question 18

Below is the structure for the amino acid alanine. Alanine can undergo an internal acid-base reaction. In this reaction, the -NH₂ group functions as a base.

Accepted Answer

The statement is true. Alanine can undergo an internal acid-base reaction where the -NH₂ group functions as a base.

Question 19

Consider the following reaction. CH₃OH(l) + CH₃OH(l) CH₃O^-(l) + CH₃OH₂⁺(l) This reaction could be classified as both an autoionization reaction and a proton transfer reaction.

Accepted Answer

The answer of Consider the following reaction. CH₃OH(l) + CH₃OH(l)...

Question 20

In converting from the pH of a solution to the corresponding H₃O⁺ concentration, the following equation should be used. [H₃O⁺] = 10^-pH

Accepted Answer

The given equation ([H₃O⁺] = 10^-pH) is the correct formula for converting pH to concentration of H₃O⁺. Therefore, option A is true.

Quiz 7: Acids and Bases

The following is an accurate description of the ionization of HBr in water.

Both the kidneys and the carbon dioxide-carbonic acid cycle help regulate blood pH.

H+, H3O+, and OH+ are different ways of representing the species that causes a solution to be acidic.

The following solutions are ranked from the most acidic to the most basic. Most acidic urine (pH 5.89) intestine contents (pH 8.06) blood (pH 7.30) Most basic

For a healthy individual, the pH of the blood in the veins is lower than in the arteries.

Very rapid breathing can lead to a condition know as respiratory acidosis.

Adipic acid has the formula given below. This is a polyprotic acid.

A solution composed of HCl and NaCl would produce an effective buffer.

Which of the following is present in pure water?

The following represents the structure of a hydronium ion.

A solution is 0.10 M in ascorbic acid (Vitamin C), H2C6H6O6, and 0.10 M in sodium ascorbate, NaHC6H6O6. When base is added to the solution, H2C6H6O6 neutralizes the added base.

The molar concentration of H3O+ in an aqueous solution would be increased by the addition of KOH.

Adipic acid has the formula given below. Thus substance would be classified as amphiprotic.

An aqueous solution contains a [H3O+] that is 1.0 × 10-3 M. What is the [OH-] of this solution?

Nitroaniline (C6H6N2O2) is a weak base. This would indicate that the pH of a 0.010 M solution of nitroaniline will be less than 7.

The pKa of lactic acid is 3.86, an equimolar solution of lactic acid and potassium lactate will have a pH of 7.72.

The range of breaths per minute, also known as respiratory rate, for a normal, healthy adult is 12-20 breaths per minute. A breathing rate of higher than this is termed hyperventilation.

Below is the structure for the amino acid alanine. Alanine can undergo an internal acid-base reaction. In this reaction, the -NH2 group functions as a base.

Consider the following reaction. CH3OH(l) + CH3OH(l) CH3O-(l) + CH3OH2+(l) This reaction could be classified as both an autoionization reaction and a proton transfer reaction.

In converting from the pH of a solution to the corresponding H3O+ concentration, the following equation should be used. [H3O+] = 10-pH