Deck 9: Acids and Bases

Question 1

An Arrhenius acid is

A)a compound that contains hydroxide and dissolves in water to form OH^-.
B)a compound that is a proton donor.
C)a compound that is a proton acceptor.
D)a compound that contains a hydrogen atom and dissolves in water to form a hydrogen ion, H⁺.

Answer 1

D

Question 2

Which species is the conjugate base of NH₃?

A)NH₄⁺
B)NH₂
C)NH₂^-
D)H₂O
E)NH₄OH

Answer 2

C

Question 3

In the acid-base reaction: HCN(aq)+ F^-(aq) CN^-(aq)+ HF(aq), where K_a (HCN)= 4.9 × 10^-10 and K_a (HF)= 7.2 × 10^-4, the

A)products are favored.
B)reactants are favored.

Answer 3

B

Question 4

Which species can act as a Brønsted-Lowry acid?

A)CO₃^2-
B)HBr
C)Br₂
D)LiOH

Question 5

Which ion is the strongest base?

A)Br^-
B)F^-
C)I^-
D)NO₃^-

Question 6

A Brønsted-Lowry acid is

A)a compound that contains hydroxide and dissolves in water to form OH^-.
B)a compound that is a proton donor.
C)a compound that is a proton acceptor.
D)a compound that contains a hydrogen atom and dissolves in water to form a hydrogen ion, H⁺.

Question 7

Which acid is the weakest?

A)Hydrogen sulfate ion HSO₄^- (K_a = 1.2 × 10^-2)
B)Hydrocyanic acid HCN (K_a = 4.9 × 10^-10)
C)Hydrofluoric acid HF (K_a = 7.2 × 10^-4)
D)Ammonium ion NH₄⁺ (K_a = 5.6 × 10^-10)

Question 8

Which species is the conjugate acid of HCO₃^-?

A)CO₃^2-
B)H₂CO₃
C)CO₂
D)H₂O

Question 9

Which compound is a weak acid?

A)HNO₃
B)HBr
C)CH₃COOH
D)H₂SO₄

Question 10

Which species is a diprotic acid?

A)Mg(OH)₂
B)CH₃COOH
C)H₂
D)H₂CO₃

Question 11

Which solution has the highest pH?

A)4.3 × 10^-8 M ^-OH
B)1.0 × 10^-7 M ^-OH
C)5.1 × 10^-2 M H₃O⁺
D)1.9 × 10^-8 M ^-OH
E)1.0 × 10^-2 M H₃O⁺

Question 12

Which acid has the strongest conjugate base?

A)Hydrogen sulfate ion HSO₄^- (K_a = 1.2 × 10^-2)
B)Hydrocyanic acid HCN (K_a = 4.9 × 10^-10)
C)Hydrofluoric acid HF (K_a = 7.2 × 10^-4)
D)Ammonium ion NH₄⁺ (K_a = 5.6 × 10^-10)

Question 13

Which species can act as a Brønsted-Lowry base?

A)CO₃^2-
B)HBr
C)H₂CO₃
D)NH₄⁺

Question 14

Which acid is the strongest?

A)Hydrogen sulfate ion HSO₄^- (K_a = 1.2 × 10^-2)
B)Hydrocyanic acid HCN (K_a = 4.9 × 10^-10)
C)Hydrofluoric acid HF (K_a = 7.2 × 10^-4)
D)Ammonium ion NH₄⁺ (K_a = 5.6 × 10^-10)

Question 15

The [H₃O⁺] in a cabernet sauvignon wine is 5.9 × 10^-4 M. What is the [^-OH] in this wine?

A)5.9 × 10^-4 M ^-OH
B)1.0 × 10^-7 M ^-OH
C)5.9 × 10^-18 M ^-OH
D)1.7 × 10^-11 M ^-OH
E)1.0 × 10^-14 M ^-OH

Question 16

In the acid-base reaction: F^-(aq)+ HNO₃(aq) HF(aq)+ NO₃^-(aq)

A)F^- is the acid and its conjugate base is HF, and HNO₃ is the base and its conjugate acid is NO₃^-(aq).
B)HNO₃ is the acid and its conjugate base is NO₃^-(aq), and F^- is the base and its conjugate acid is HF.
C)F^- is the acid and its conjugate base is NO₃^-(aq), and HNO₃ is the base and its conjugate acid is HF.
D)HNO₃ is the acid and its conjugate base is HF, and F^- is the base and its conjugate acid is NO₃^-(aq).

Question 17

Which solution has the highest pH?

A)4.3 × 10^-8 M H₃O⁺
B)1.0 × 10^-7 M H₃O⁺
C)5.1 × 10^-2 M H₃O⁺
D)1.9 × 10^-8 M H₃O⁺
E)1.0 × 10^-2 M H₃O⁺

Question 18

The [^-OH] in a sample of egg whites is 6.3 × 10^-7 M. What is the [H₃O⁺] in these egg whites?

A)6.3 × 10^-7 M H₃O⁺
B)1.0 × 10^-7 M H₃O⁺
C)6.3 × 10^-21 M H₃O⁺
D)1.6 × 10^-8 M H₃O⁺
E)1.0 × 10^-14 M H₃O⁺

Question 19

Ammonia, NH₃, is an example of a

A)strong acid
B)strong base
C)weak acid
D)weak base

Question 20

What is the expression for K_w, the ion-product constant for water?

A)K_w = [H₂O]²
B)K_w =
C)K_w =
D)K_w =

Question 21

What is the pH of a cleaning solution with a [H₃O⁺] = 7.4 × 10^-9 M H₃O⁺?

A)5.9
B)7.13
C)8.13
D)5.87

Question 22

Which buffer solution has the lowest pH (HF has K_a = 7.2 × 10^-4)?

A)0.10 M HF and 0.10 M NaF
B)0.20 M HF and 0.20 M NaF
C)0.20 M HF and 0.10 M NaF
D)0.10 M HF and 0.20 M NaF
E)All of the buffer solutions described above have the same pH.

Question 23

Which salt forms a solution with a pH < 7 when dissolved in water?

A)RbI
B)NaCH₃COO
C)LiNO₂
D)(NH₄)₂SO₄

Question 24

How many milliliters of 0.653 M NaOH are needed to neutralize 25.0 mL of a 1.02 M HBr solution? The neutralization reaction is: NaOH(aq)+ HBr(aq) $\rightarrow$ H₂O(l)+ NaBr(aq)

A)16.0 mL NaOH
B)25.5 mL NaOH
C)39.1 mL NaOH
D)16.3 mL NaOH

Question 25

What is the molarity of an HNO₃ solution if 24.1 mL of a 0.250 M Ba(OH)₂ solution are needed to titrate a 15.0 mL sample of the acid according to the equation below? Ba(OH)₂(aq)+ 2 HNO₃(aq) 2 H₂O(l)+ Ba(NO₃)₂(aq)

A)0.402 M HNO₃
B)0.156 M HNO₃
C)0.311 M HNO₃
D)0.201 M HNO₃
E)0.803 M HNO₃

Question 26

Which solution has the lowest pH?

A)1.3 × 10^-8 M ^-OH
B)1.0 × 10^-7 M ^-OH
C)5.1 × 10^-2 M ^-OH
D)3.9 × 10^-8 M ^-OH
E)2.3 × 10^-3 M ^-OH

Question 27

What is the conjugate base of the hydronium ion, H₃O⁺?

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

Question 28

What are the products of the acid-base reaction of sodium carbonate with acetic acid?

A)CO₂(g)+ H₂O(l)+ 2 NaCH₃COO(aq)
B)5 CO₂(g)+ 2 H₂O(l)+ 2 NaOH(aq)
C)H₂CO₃(aq)+ H₂O(l)+ 2 NaOH(aq)
D)CO(g)+ H₂O(l)+ 2 NaCH₃COO(aq)

Question 29

What is the pH of a peach with a [^-OH] = 3.2 × 10^-11 M ^-OH?

A)11.32
B)10.49
C)3.51
D)3.2

Question 30

The pH of a lime is 1.90. What is the [H₃O⁺]?

A)1.3 × 10^-2 M H₃O⁺
B)1.3 × 10¹² M H₃O⁺
C)7.9 × 10¹ M H₃O⁺
D)7.9 × 10^-13 M H₃O⁺
E)1.9 M H₃O⁺

Question 31

The pH of normal blood is 7.4. The pH of a diabetic's blood was determined to be 6.4. Which comparison of these two blood samples is accurate?

A)The diabetic's blood has a lower [H₃O⁺] than normal blood.
B)The diabetic's blood is more acidic than normal blood.
C)Normal blood has a lower [OH^-] than the diabetic's blood.
D)Normal blood has a higher [H₃O⁺] than the diabetic's blood.

Question 32

What is the pH of a buffer that contains 0.15 M CH₃COOH and 0.10 M NaCH₃COO (K_a = 1.8 × 10^-5)?

A)4.74
B)7.00
C)4.57
D)4.92

Question 33

Which term correctly describes the medical condition in which the pH of blood is greater than 7.45, and therefore the blood is more basic than normal?

A)respiratory alkalosis
B)alkalosis
C)respiratory acidosis
D)acidosis

Question 34

An aqueous solution with a low pH is necessary for a certain industrial process. Which of the following solutions would have the lowest pH?

A)2.0 M NaOH
B)0.5 M HCl
C)1.0 M acetic acid, CH₃COOH
D)1.0 M HCl
E)0.15 M NaOH

Question 35

What is the net ionic equation for the acid-base reaction of hydrobromic acid with sodium hydroxide?

A)NaOH(aq)+ HBr(aq) $\rightarrow$ H₂O(l)+ NaBr(aq)
B)Na⁺(aq)+ ^-OH(aq)+ H⁺(aq)+ Br^-(aq) $\rightarrow$ H₂O(l)+ Na⁺(aq)+ Br^-(aq)
C)Na⁺(aq)+ ^-OH(aq)+ H⁺(aq)+ Br^-(aq) $\rightarrow$ H⁺(aq)+ ^-OH(aq)+ Na⁺(aq)+ Br^-(aq)
D)^-OH(aq)+ H⁺(aq) $\rightarrow$ H₂O(l)

Question 36

Which solution containing an equal number of moles of each of the substances is a buffer?

A)HCl and NaCl
B)HNO₂ and HNO₃
C)CH₃COOH and NaCH₃COO
D)H₂CO₃ and CO₃^2-
E)More than one of the solutions above is a buffer.

Question 37

What is the molarity of an HCl solution if 43.6 mL of a 0.125 M KOH solution are needed to titrate a 25.0 mL sample of the acid according to the equation below? KOH(aq)+ HCl(aq) $\rightarrow$ H₂O(l)+ KCl(aq)

A)0.218 M HCl
B)0.573 M HCl
C)0.0717 M HCl
D)4.58 M HCl
E)1.74 M HCl

Question 38

Which diagram properly depicts the dissolved species present in an aqueous solution of KOH? (water molecules are not shown)

A)
B)
C)
D)

Question 39

Which salt forms a basic solution when dissolved in water?

A)KCl
B)NH₄Br
C)LiNO₃
D)Na₃PO₄

Question 40

What is the balanced equation for the acid-base reaction of nitrous acid with lithium hydroxide?

A)LiOH(aq)+ HNO₃(aq) H₂O(l)+ LiNO₃(aq)
B)Li(OH)₂(aq)+ 2 HNO₃(aq) 2 H₂O(l)+ Li(NO₃)₂(aq)
C)LiOH(aq)+ HNO₂(aq) H₂O(l)+ LiNO₂(aq)
D)2 LiOH(aq)+ H₂NO₂(aq) 2 H₂O(l)+ Li₂NO₂(aq)

Question 41

All compounds can be classified as either an acid or a base.

Question 42

The pH of a 1.0 × 10^-5 M H₃O⁺ solution is 5.00.

Question 43

A solution in which [^-OH] = 6.3 × 10^-7 M has a higher pH than a solution with a [^-OH] = 4.3 × 10^-2 M.

Question 44

An aqueous solution of NaHCO₃ is basic.

Question 45

A sample of water from the Chesapeake Bay has [H₃O⁺]=3.1 × 10^-9 M. Which statement below accurately describes this water sample?

A)The pH of the water sample is 7.5.
B)The water sample is a basic solution.
C)The water sample doesn't contain any hydroxide ions.
D)The water sample has a higher concentration of hydronium ions than pure water does.

Question 46

When phosphoric acid (H₃PO₄)dissolves in water, the equilibrium shown below is established. If K_a = 7.5 × 10^-3 for H₃PO₄, which statement concerning an aqueous solution of phosphoric acid is correct?
H₃PO₄ + H₂O H₃O⁺ + H₂PO₄^-

A)An aqueous solution of phosphoric acid contains mainly H₃PO₄ molecules.
B)An aqueous solution of phosphoric acid contains predominantly H₃O⁺ and H₂PO₄^- ions.
C)An aqueous solution of phosphoric acid contains equal amounts of H₃O⁺ and H₃PO₄.
D)An aqueous solution of phosphoric acid contains a greater concentration of dissolved ions than it does neutral phosphoric acid molecules.

Question 47

If two solutions differ in their [H₃O⁺] by a factor of 2.0, the difference in their pH will be 2.0.

Question 48

The pH of a 1.0 × 10^-6 M ^-OH solution is 6.00.

Question 49

The value of K_w = 1.0 × 10^-14 at all temperatures below 100 °C.

Question 50

An aqueous solution of KCl has a lower pH than an aqueous solution of Li₂SO₃.

Question 51

A solution in which [H₃O⁺] = 7.4 × 10^-5 M has a higher pH than a solution with a [^-OH] = 4.8 × 10^-8 M.

Question 52

The products are favored in the acid-base reaction: HI(aq)+ NH₃(aq) NH₄⁺(aq)+ I^-(aq).

Question 53

A salt derived from a strong base and a weak acid forms an acidic solution.

Question 54

In an acidic solution, [H₃O⁺] > [^-OH].

Question 55

Normal gastric juice has a pH of about 2. Assuming that normal gastric juice is primarily aqueous HCl, what is the concentration of HCl in the stomach?

A)2 M HCl
B)1.0 × 10² M HCl
C)0.01 M HCl
D)0.14 M HCl

Question 56

Although a Brønsted-Lowry acid must contain a hydrogen atom, it may be a neutral molecule or contain a net positive or negative charge.

Question 57

A sample of urine has a pH of 8.2. Which statement describing the urine sample is NOT true?

A)The urine sample is basic.
B)The urine sample has a hydronium ion concentration greater than that of a neutral solution.
C)The urine sample has a hydroxide ion concentration greater than its hydronium ion concentration.
D)The urine sample has a hydroxide ion concentration greater than 1.0 × 10^-7.

Question 58

A compound can be an acid or a base, but not both.

Question 59

The acid-base indicator phenolphthalein is colorless in acidic solutions and bright pink in basic solutions.

Question 60

The value of K_w applies to any aqueous solution at 25 °C , not just pure water.

Question 61

The addition of a base to water decreases the pH of the solution.

Question 62

Two species that differ by the presence of a proton are called a conjugate acid-base pair.

Question 63

An aqueous solution whose pH is greater than 7 has a higher [H₃O⁺] than pure water itself.

Question 64

The principal buffer in the blood is carbonic acid/bicarbonate (H₂CO₃/HCO₃^-), keeping the normal blood pH of a healthy individual in the range of 7.35 to 7.45.

Question 65

OH^- and NH₄⁺ are both examples of Brønsted-Lowry bases.

Question 66

If the pH of blood is lower than 7.35, the blood is more acidic than normal, and the condition is called alkalosis.

Question 67

In an acid-base reaction, a proton is transferred from the acid (HA)to the base (B:).

Question 68

All salts where the anion is derived from a strong acid form basic solutions.

Question 69

In the reaction: SO₃^2-(aq)+ H₂O(l) HSO₃^-(aq)+ ^-OH(aq), H₂O acts as a Brønsted-Lowry acid.

Question 70

A Brønsted-Lowry base must contain a lone pair of electrons.

Question 71

HOBr and CH₃CH₂CH₂COOH are both examples of Brønsted-Lowry acids.

Question 72

An aqueous solution containing an equal number of moles of Na₂HPO₄ and H₃PO₄ is an example of a buffer solution.

Question 73

Consider two acids, A and B. If acid A is weaker than acid B, then acid B dissociates in water to a greater extent than acid A.

Question 74

Consider two acids, A and B. If acid A is stronger than acid B, then the conjugate base of B is stronger than the conjugate base of A.

Question 75

An aqueous solution containing an equal number of moles of NaF and HF is an example of a buffer solution.

Question 76

For a solution labeled 0.15 M CH₃COOH, the [H₃O⁺] is 0.15 M.

Question 77

Water is amphoteric; it can act as an acid or a base.

Question 78

Most acids are weak acids.

Question 79

The addition of an acid to water increases the [H₃O⁺] of the solution and increases the solution pH.

Question 80

A solution containing a low concentration HCl is a weak acid.