Acids, Bases and Buffers: Interactive Learning Quizzes

Question 1

Which compound listed below is a base?

Accepted Answer

Sodium hydroxide (NaOH)

Answer

Hydrochloric acid (HCl)

Answer

Water (H2O)

Answer

Carbon dioxide (CO2)

Question 2

During an acid-base reaction, which of the following is formed?

Accepted Answer

Salt and water

Answer

Energy

Answer

Gas

Answer

Colorful compounds

Question 3

What is the main purpose of using a buffer solution?

Accepted Answer

To maintain a stable pH

Answer

To neutralize acids

Answer

To precipitate salts

Answer

To alter the color of solutions

Question 4

Which of the following is used to determine the concentration of an unknown solution or solute?

Accepted Answer

Titration

Answer

Neutralization reaction

Answer

Precipitation reaction

Answer

Color change reaction

Question 5

What point in a titration indicates the completion of the reaction?

Accepted Answer

Equivalence point

Answer

Color change point

Answer

Neutralization point

Answer

Initial point

Question 6

Which compound listed below is a strong base?

Accepted Answer

Sodium hydroxide (NaOH)

Answer

Ammonia (NH3)

Answer

Calcium hydroxide (Ca(OH)2)

Answer

Magnesium hydroxide (Mg(OH)2)

Question 7

Which statement does NOT describe a characteristic of acids?

Accepted Answer

Have a pH greater than 7

Answer

React with metals to produce hydrogen gas

Answer

Turn blue litmus paper red

Answer

Have a sour taste

Question 8

In the Bronsted-Lowry theory, what is the conjugate acid of NH3?

Accepted Answer

NH4+

Answer

H3O+

Answer

OH-

Answer

N2H4

Question 9

What is the pH of a solution with a hydroxide ion concentration of 1 × 10⁻⁷ M?

Accepted Answer

7

Answer

0

Answer

14

Question 10

Identify the conjugate base of the weak acid HF:

Accepted Answer

F⁻

Answer

H₂F⁻

Answer

OH⁻

Answer

H₃O⁺

Question 11

What is the primary purpose of a titration experiment?

Accepted Answer

Determining the concentration of an unknown solution

Answer

Identifying an unknown substance

Answer

Measuring the pH of a solution

Answer

Preparing a buffer solution

Question 12

Which species is considered a Lewis base?

Accepted Answer

NH₃

Answer

H₂O

Answer

HCl

Answer

NaOH

Question 13

Determine the oxidation number of nitrogen in nitric acid (HNO₃).

Accepted Answer

+7

Answer

-3

Answer

+3

Answer

+5

Question 14

According to the Bronsted-Lowry concept, which of these is the strongest base?

Accepted Answer

OH-

Answer

H2O

Answer

NH3

Answer

CH3COOH

Question 15

Calculate the pH of a solution with a [H+] concentration of 10^-7 M.

Accepted Answer

7

Answer

0

Answer

10

Answer

14

Question 16

Identify the conjugate base of hydrochloric acid.

Accepted Answer

Chloride ion

Answer

Hydroxide ion

Answer

Water

Answer

Sulfate ion

Question 17

Explain the key difference between strong and weak acids.

Accepted Answer

Strong acids completely dissociate in water, while weak acids partially dissociate.

Answer

Weak acids are more corrosive than strong acids.

Answer

Strong acids have a higher pH than weak acids.

Answer

Weak acids conduct electricity better than strong acids.

Question 18

Select the correct definition of a titration curve.

Accepted Answer

A graphical representation of pH versus volume of titrant added

Answer

A graphical representation of concentration versus time

Answer

A graphical representation of temperature versus pressure

Answer

A graphical representation of absorbance versus wavelength

Question 19

Which species is the conjugate base of H3O+?

Accepted Answer

OH-

Answer

H2O

Answer

H2SO4

Answer

SO42-

Question 20

A solution has a pH of 3. What is the molarity of H+ ions in the solution?

Accepted Answer

1 x 10^-3 M

Answer

1 x 10^3 M

Answer

1 x 10^-7 M

Answer

1 x 10^7 M

Question 21

What is the primary function of a buffer in a chemical system?

Accepted Answer

To maintain a stable pH within a specific range

Answer

To increase the acidity of the solution

Answer

To decrease the basicity of the solution

Answer

To catalyze chemical reactions

Question 22

Which of the following is NOT an application of buffers in everyday life?

Accepted Answer

Battery production

Answer

Blood regulation

Answer

Food preservation

Answer

Water purification

Question 23

Which indicator is commonly used to determine the endpoint of a strong acid-strong base titration?

Accepted Answer

Phenolphthalein

Answer

Methyl orange

Answer

Litmus

Answer

Universal indicator

Question 24

Identify the conjugate acid of HCO3-

Accepted Answer

H2CO3

Answer

OH-

Answer

H+

Answer

CO32-

Question 25

Which of the following substances is a weak base?

Accepted Answer

NH3

Answer

NaOH

Answer

KOH

Answer

Ca(OH)2

Question 26

Calculate the pH of a 0.1 mol/L solution of NaOH.

Accepted Answer

13

Answer

1

Answer

7

Answer

14

Question 27

Identify the conjugate base of a weak acid.

Accepted Answer

OH-

Answer

H+

Answer

Cl-

Answer

Na+

Question 28

Identify the conjugate acid of the base CH3COO-.

Accepted Answer

CH3COOH

Answer

H2O

Answer

NaOH

Answer

HCl

Question 29

Predict the pH at the endpoint of a titration between a weak acid and a strong base.

Accepted Answer

Less than 7

Answer

7

Answer

Greater than 7

Answer

Cannot be determined without additional information

Question 30

Classify hydrochloric acid as an electrolyte.

Accepted Answer

Strong electrolyte

Answer

Weak electrolyte

Answer

Non-electrolyte

Question 31

Which of the following acids has the strongest conjugate base?

Accepted Answer

H2SO4

Answer

HCl

Answer

HNO3

Answer

CH3COOH

Question 32

During the titration of a weak acid with a strong base, the titration endpoint is reached when:

Accepted Answer

The equivalence point is reached.

Answer

The pH of the solution is exactly 7.

Answer

The solution becomes colorless.

Answer

The indicator changes color.

Question 33

Which of the following is classified as a strong acid?

Accepted Answer

Hydrochloric acid

Answer

Ethanoic acid

Answer

Citric acid

Answer

Carbonic acid

Question 34

In a neutral aqueous solution, the pH value is:

Accepted Answer

7

Answer

0

Answer

14

Answer

10

Question 35

The primary function of a buffer in a chemical system is to:

Accepted Answer

Maintain a stable pH

Answer

Increase the solubility of ionic compounds

Answer

Act as a catalyst

Answer

Neutralize acids or bases

Question 36

When a strong acid is added to a solution, what happens to the pH?

Accepted Answer

Decreases

Answer

Increases

Answer

Remains the same

Answer

Cannot be determined

Question 37

Which of the following processes involves neutralizing an acid with a base?

Accepted Answer

Neutralizing an acid with a base

Answer

Measuring the amount of acid in a solution

Answer

Measuring the pH of a solution

Answer

Mixing two solutions together

Question 38

During a titration, the equivalence point is reached when:

Accepted Answer

The moles of acid equal the moles of base

Answer

The pH is exactly 7

Answer

The solution changes a specific color

Answer

The temperature of the solution is highest

Question 39

Which of the following is an example of a Lewis acid?

Accepted Answer

AlCl3

Answer

HCl

Answer

NaOH

Answer

NH3

Question 40

The equilibrium constant for the dissolution reaction is known as the:

Accepted Answer

Ksp value

Answer

Molar solubility

Answer

Ion concentration

Answer

pH value

Question 41

What is the pH of a 0.1 M solution of hydrochloric acid?

Accepted Answer

0

Answer

1

Answer

7

Answer

14

Question 42

Which of the following is a weak acid?

Accepted Answer

Acetic acid

Answer

Hydrochloric acid

Answer

Sulfuric acid

Answer

Nitric acid

Question 43

What is the conjugate base of hydrochloric acid?

Accepted Answer

Chloride ion

Answer

Hydrogen ion

Answer

Hydroxide ion

Answer

Sulfate ion

Question 44

What is the pH of a solution that has a hydrogen ion concentration of 10^-5 M?

Accepted Answer

5

Answer

7

Answer

9

Answer

11

Question 45

Which of the following is a buffer system?

Accepted Answer

Acetic acid and sodium acetate

Answer

Hydrochloric acid and sodium hydroxide

Answer

Sodium chloride and water

Answer

Potassium hydroxide and sulfuric acid

Question 46

What is the primary function of a buffer solution in a biological system?

Accepted Answer

Maintaining a relatively constant pH

Answer

Transporting oxygen

Answer

Regulating blood sugar levels

Answer

Digesting food

Question 47

Which of the following is a common buffer system in the human body?

Accepted Answer

Carbonic acid/bicarbonate ion

Answer

Acetic acid/acetate ion

Answer

Phosphoric acid/phosphate ion

Answer

Sulfuric acid/sulfate ion

Question 48

What is the expected pH of a buffer solution that contains equal concentrations of 0.1 M acetic acid and 0.1 M sodium acetate?

Accepted Answer

4.76

Answer

7.00

Answer

9.24

Answer

11.00

Question 49

Which of the following factors directly influences the pH of a buffer solution?

Accepted Answer

Concentration of the acid and base

Answer

Temperature

Answer

Pressure

Answer

Volume of the solution

Question 50

Select the accurate definition of a buffer solution:

Accepted Answer

A solution that resists pH changes upon the addition of small amounts of either acid or base.

Answer

A solution with a precise pH of 7.

Answer

A solution containing a weak acid and its conjugate base.

Answer

A solution containing a strong acid and its conjugate base.

Question 51

Identify the weak acid from the following compounds:

Accepted Answer

Acetic acid

Answer

Hydrochloric acid

Answer

Sulfuric acid

Answer

Sodium hydroxide

Question 52

Determine the conjugate base of hydrocyanic acid (HCN):

Accepted Answer

CN-

Answer

H+

Answer

OH-

Answer

HCO3-

Question 53

Estimate the approximate pH of a 0.1 mol/L solution of hydrochloric acid:

Accepted Answer

1

Answer

3

Answer

7

Answer

13

Question 54

Which of the following solutions is considered a buffer solution?

Accepted Answer

A solution of 0.1 mol/L NH3 and 0.1 mol/L NH4Cl

Answer

Pure water

Answer

A solution of 0.1 mol/L HCl and 0.1 mol/L NaCl

Answer

A solution of 0.1 mol/L NaOH and 0.1 mol/L NaCl

Question 55

Explain the primary purpose of using a buffer solution in a chemical reaction:

Accepted Answer

To maintain a stable pH

Answer

To speed up the reaction

Answer

To slow down the reaction

Answer

To prevent the formation of precipitates

Question 56

Identify the factor that primarily influences the strength of a buffer solution:

Accepted Answer

The concentration of the weak acid and its conjugate base

Answer

The temperature of the solution

Answer

The pH of the solution

Answer

The presence of other ions in the solution

Question 57

Which of the following bases is the weakest?

Accepted Answer

Magnesium hydroxide (Mg(OH)2)

Answer

Sodium hydroxide (NaOH)

Answer

Potassium hydroxide (KOH)

Answer

Calcium hydroxide (Ca(OH)2)

Question 58

What is the primary function of a buffer in a chemical system?

Accepted Answer

To maintain a stable pH

Answer

To increase the acidity

Answer

To decrease the basicity

Answer

To change the color of the solution

Question 59

Which of the following characteristics is associated with strong acids?

Accepted Answer

Completely ionized in water

Answer

Partially ionized in water

Answer

Weak electrical conductor

Answer

High pH

Question 60

What is the primary purpose of using a pH meter?

Accepted Answer

To accurately measure the concentration of hydrogen ions in a solution

Answer

To determine the presence of an acid or base

Answer

To calibrate other pH meters

Answer

To determine the strength of an acid or base

Question 61

What is the pH of a neutral solution at 25°C?

Accepted Answer

7

Answer

0

Answer

14

Answer

28

Question 62

Which of the following salts is capable of forming a buffer solution?

Accepted Answer

Sodium acetate

Answer

Sodium chloride

Answer

Potassium nitrate

Answer

Calcium sulfate

Question 63

What is the conjugate base of H2SO4?

Accepted Answer

SO42-

Answer

HSO4-

Answer

H3O+

Answer

S2O72-

Question 64

What is the primary function of a buffer solution in a chemical system?

Accepted Answer

To maintain a stable pH

Answer

To increase the acidity of the solution

Answer

To decrease the basicity of the solution

Answer

To prevent the formation of precipitates