Question 1

The species that remains after an acid donates a proton is called its conjugate base.What is the conjugate base of the hydronium ion, H3O+?

Accepted Answer

A) OH- 
B) H2O- 
C) H2O 
D) H2O+ 
E) H3O+ has no conjugate base. 
A) OH- 
B) H2O- 
C) H2O 
D) H2O+ 
E) H3O+ has no conjugate base.

Question 2

The ion-product of water is affected by a change in temperature.

Accepted Answer

A) True 
 B)False

Question 3

Which statement correctly describes conjugate acids and bases according to the Brønsted-Lowry theory?

Accepted Answer

A) A conjugate base is the species formed when an acid donates a proton; a conjugate acid is the species formed when a base accepts a proton. 
B) A conjugate base is the species formed when an acid accepts a proton; a conjugate acid is the species formed when a base donates a proton. 
C) A conjugate acid is the species formed when an acid donates a proton; a conjugate base is the species formed when a base accepts a proton. 
D) A conjugate acid is an acid that does not completely transfer a proton to water; a conjugate base is a base that does not completely accept a proton from water. 
E) A conjugate acid is the solution formed when an acid is added to water; a conjugate base is the solution formed when a base is added to water. 
A) A conjugate base is the species formed when an acid donates a proton; a conjugate acid is the species formed when a base accepts a proton. 
B) A conjugate base is the species formed when an acid accepts a proton; a conjugate acid is the species formed when a base donates a proton. 
C) A conjugate acid is the species formed when an acid donates a proton; a conjugate base is the species formed when a base accepts a proton. 
D) A conjugate acid is an acid that does not completely transfer a proton to water; a conjugate base is a base that does not completely accept a proton from water. 
E) A conjugate acid is the solution formed when an acid is added to water; a conjugate base is the solution formed when a base is added to water.

Question 4

A pH of 0 is considered neutral.

Accepted Answer

A) True 
 B)False

Question 5

All Brønsted-Lowry bases contain hydroxide.

Accepted Answer

A) True 
 B)False

Question 6

A patient's urine sample gave a reading of 8.2.What is the value of [H3O+] in this solution?

Accepted Answer

A) 6.0 × 10-9 M 
B) 0.91 M 
C) 1.6 × 10-8 M 
D) 1.6 × 108 M 
E) 2.7 × 10-4 M 
A) 6.0 × 10-9 M 
B) 0.91 M 
C) 1.6 × 10-8 M 
D) 1.6 × 108 M 
E) 2.7 × 10-4 M

Question 7

Titration of 25.0 mL of an HCl solution of unknown concentration requires 14.8 mL of 0.100 M NaOH.What is the molar concentration of the HCl solution? NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

Accepted Answer

A) 0.592 M 
B) 5.87 M 
C) 0.0592 M 
D) 0.0692 M 
E) 1.25 M 
A) 0.592 M 
B) 5.87 M 
C) 0.0592 M 
D) 0.0692 M 
E) 1.25 M

Question 8

A buffer solution is prepared by placing twice the concentration of propanoic acid (C2H5COOH, Ka=1.34 ×10-5) as the concentration of its conjugate base sodium propanoate into a flask.The pH of the resulting buffer solution is best described as which of the following?

Accepted Answer

A) less than 4.87 
B) 4.87 
C) between 4.87 and 9.00 
D) greater than 11.00 
E) Undeterminable; the concentrations of the acid and conjugate base must be given. 
A) less than 4.87 
B) 4.87 
C) between 4.87 and 9.00 
D) greater than 11.00 
E) Undeterminable; the concentrations of the acid and conjugate base must be given.

Question 9

Which statement concerning the relative strength of acids is FALSE?

Accepted Answer

A) Strong and weak acids differ in their extent of proton transfer to water. 
B) Strong acids are good proton donors; weak acids are poor proton donors. 
C) A strong acid completely transfers its protons to water; a weak acid only partially transfers its protons to water. 
D) Strong acids produce strong conjugate bases; weak acids produce weak conjugate bases. 
E) A strong acid produces more hydronium ions in water than a weak acid of the same concentration. 
A) Strong and weak acids differ in their extent of proton transfer to water. 
B) Strong acids are good proton donors; weak acids are poor proton donors. 
C) A strong acid completely transfers its protons to water; a weak acid only partially transfers its protons to water. 
D) Strong acids produce strong conjugate bases; weak acids produce weak conjugate bases. 
E) A strong acid produces more hydronium ions in water than a weak acid of the same concentration.

Question 10

For the reaction shown below, which of the following is a conjugate acid-base pair? C5H5N(aq) + H2O(l)   C5H5NH+(aq) + OH−(aq)

Accepted Answer

A) C5H5N, H2O 
B) C5H5N, C5H5NH+ 
C) C5H5NH+, OH− 
D) H2O, OH− 
E) C5H5N, C5H5NH+ and H2O, OH− 
A) C5H5N, H2O 
B) C5H5N, C5H5NH+ 
C) C5H5NH+, OH− 
D) H2O, OH− 
E) C5H5N, C5H5NH+ and H2O, OH−

Question 11

What is the hydronium ion concentration of a solution with a pH of 6.0?

Accepted Answer

A) 1 × 106 M 
B) 1 × 10-6 M 
C) 6 × 101 M 
D) 6 × 10-1 M 
E) 6 × 10-14 M 
A) 1 × 106 M 
B) 1 × 10-6 M 
C) 6 × 101 M 
D) 6 × 10-1 M 
E) 6 × 10-14 M

Question 12

A solution containing a buffer has an initial pH of 8.78.If a student adds 5 drops of NaCl(aq) to this solution, what would be a reasonable pH for the resulting solution?

Accepted Answer

A) 5.22 
B) 7.00 
C) 8.64 
D) 8.78 
E) 8.89 
A) 5.22 
B) 7.00 
C) 8.64 
D) 8.78 
E) 8.89

Question 13

Sodium hydroxide (NaOH) can react with phosphoric acid (H3PO4) in a neutralization reaction.What is the reacting ratio of NaOH to H3PO4?

Accepted Answer

A) 1:1 
B) 1:3 
C) 3:8 
D) 2:7 
E) 3:1 
A) 1:1 
B) 1:3 
C) 3:8 
D) 2:7 
E) 3:1

Question 14

What is the pH of a solution that has [H3O+] = 6.0 × 10-3 M?

Accepted Answer

A) 1.7 × 10-12 
B) 2.22 
C) 3.60 
D) 5.12 
E) 11.78 
A) 1.7 × 10-12 
B) 2.22 
C) 3.60 
D) 5.12 
E) 11.78

Question 15

HCl is a strong electrolyte.A bottle of HCl contains the label 0.015 M HCl(aq).Which statement concerning this HCl solution is FALSE?

Accepted Answer

A) The solution is acidic. 
B) The pH of the solution is 1.5. 
C) The hydronium ion concentration in this solution is 0.015 M. 
D) The solution has a higher concentration of hydronium ions than hydroxide ions. 
E) The solution contains dissolved H3O+ and Cl− ions only; no HCl molecules are present. 
A) The solution is acidic. 
B) The pH of the solution is 1.5. 
C) The hydronium ion concentration in this solution is 0.015 M. 
D) The solution has a higher concentration of hydronium ions than hydroxide ions. 
E) The solution contains dissolved H3O+ and Cl− ions only; no HCl molecules are present.

Question 16

The pH of a 12.0 M solution of HCl is -1.1.

Accepted Answer

A) True 
 B)False

Question 17

Consider two beakers, one containing 1.0 M HCl and the other containing 1.0 M CH3COOH.Which solution would have the lowest pH?

Accepted Answer

A) 1.0 M CH3COOH because its solution contains a lower hydronium ion concentration than 1.0 M HCl 
B) 1.0 M HCl because its solution contains a higher hydronium ion concentration than 1.0 M CH3COOH 
C) 1.0 M HCl because its solution contains a lower hydronium ion concentration than 1.0 M CH3COOH 
D) 1.0 M CH3COOH because its solution contains a higher hydronium ion concentration than 1.0 M HCl 
E) Both solutions would have the same pH because they have the same concentration. 
A) 1.0 M CH3COOH because its solution contains a lower hydronium ion concentration than 1.0 M HCl 
B) 1.0 M HCl because its solution contains a higher hydronium ion concentration than 1.0 M CH3COOH 
C) 1.0 M HCl because its solution contains a lower hydronium ion concentration than 1.0 M CH3COOH 
D) 1.0 M CH3COOH because its solution contains a higher hydronium ion concentration than 1.0 M HCl 
E) Both solutions would have the same pH because they have the same concentration.

Question 18

Butyric acid is a weak acid.Which reaction equation properly represents the dissociation of butyric acid in water?

Accepted Answer

A) CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COO- (aq) + H3O+(aq) 
B) CH3CH2CH2COOH(aq) + H2O(l)   CH3CH2CH2COO-(aq) + H3O+(aq) 
C) CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COOH2+(aq) + OH-(aq) 
D) CH3CH2CH2COOH(aq) + H2O(l)   CH2CH2CH2COOH(aq) + H3O+(aq) 
A) CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COO- (aq) + H3O+(aq) 
B) CH3CH2CH2COOH(aq) + H2O(l)   CH3CH2CH2COO-(aq) + H3O+(aq) 
C) CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COOH2+(aq) + OH-(aq) 
D) CH3CH2CH2COOH(aq) + H2O(l)   CH2CH2CH2COOH(aq) + H3O+(aq)

Question 19

What is the conjugate acid of NH2−?

Accepted Answer

A) NH2− 
B) NH3 
C) NH4+ 
D) NH2+ 
E) NH4− 
A) NH2− 
B) NH3 
C) NH4+ 
D) NH2+ 
E) NH4−

Question 20

Which of the following compounds is NOT considered a polyprotic acid?

Accepted Answer

A) H2SO4 
B) H3PO4 
C) H2CO3 
D) H2SO3 
E) CH3COOH 
A) H2SO4 
B) H3PO4 
C) H2CO3 
D) H2SO3 
E) CH3COOH

Exam 8: Acids and Bases

The species that remains after an acid donates a proton is called its conjugate base.What is the conjugate base of the hydronium ion, H3O+?

The ion-product of water is affected by a change in temperature.

Which statement correctly describes conjugate acids and bases according to the Brønsted-Lowry theory?

A pH of 0 is considered neutral.

All Brønsted-Lowry bases contain hydroxide.

A patient's urine sample gave a reading of 8.2.What is the value of [H3O+] in this solution?

Titration of 25.0 mL of an HCl solution of unknown concentration requires 14.8 mL of 0.100 M NaOH.What is the molar concentration of the HCl solution? NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

A buffer solution is prepared by placing twice the concentration of propanoic acid (C2H5COOH, Ka=1.34 ×10-5) as the concentration of its conjugate base sodium propanoate into a flask.The pH of the resulting buffer solution is best described as which of the following?

Which statement concerning the relative strength of acids is FALSE?

For the reaction shown below, which of the following is a conjugate acid-base pair? C5H5N(aq) + H2O(l) C5H5NH+(aq) + OH−(aq)

What is the hydronium ion concentration of a solution with a pH of 6.0?

A solution containing a buffer has an initial pH of 8.78.If a student adds 5 drops of NaCl(aq) to this solution, what would be a reasonable pH for the resulting solution?

Sodium hydroxide (NaOH) can react with phosphoric acid (H3PO4) in a neutralization reaction.What is the reacting ratio of NaOH to H3PO4?

What is the pH of a solution that has [H3O+] = 6.0 × 10-3 M?

HCl is a strong electrolyte.A bottle of HCl contains the label 0.015 M HCl(aq).Which statement concerning this HCl solution is FALSE?

The pH of a 12.0 M solution of HCl is -1.1.

Consider two beakers, one containing 1.0 M HCl and the other containing 1.0 M CH3COOH.Which solution would have the lowest pH?

Butyric acid is a weak acid.Which reaction equation properly represents the dissociation of butyric acid in water?

What is the conjugate acid of NH2−?

Which of the following compounds is NOT considered a polyprotic acid?

Chemistry:methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, Chemical Changes, and the Chemical Equation

States of Matter- Gases, Liquids, and Solids

Solutions

Energy, Rate and Equilibrium

The Nucleus, Radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry- the Saturated Hydrocarbons

The Unsaturated Hydrocarbons- Alkenes, Alkynes, and Aromatics

Alcohols, Phenols, Thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

Filters

The species that remains after an acid donates a proton is called its conjugate base.What is the conjugate base of the hydronium ion, H₃O⁺?

A patient's urine sample gave a reading of 8.2.What is the value of [H₃O⁺] in this solution?

Titration of 25.0 mL of an HCl solution of unknown concentration requires 14.8 mL of 0.100 M NaOH.What is the molar concentration of the HCl solution? NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l)

A buffer solution is prepared by placing twice the concentration of propanoic acid (C₂H₅COOH, K_a=1.34 ×10^-5) as the concentration of its conjugate base sodium propanoate into a flask.The pH of the resulting buffer solution is best described as which of the following?

For the reaction shown below, which of the following is a conjugate acid-base pair? C₅H₅N(aq) + H₂O(l) C₅H₅NH⁺(aq) + OH⁻(aq)

Sodium hydroxide (NaOH) can react with phosphoric acid (H₃PO₄) in a neutralization reaction.What is the reacting ratio of NaOH to H₃PO₄?

What is the pH of a solution that has [H₃O⁺] = 6.0 × 10^-3 M?

Consider two beakers, one containing 1.0 M HCl and the other containing 1.0 M CH₃COOH.Which solution would have the lowest pH?

What is the conjugate acid of NH₂⁻_?