Deck 9: Acids and Bases

Question 1

Which species is the conjugate base of NH₃?

A)NH₄⁺
B)NH₂
C)NH₂^-
D)H₂O
E)NH₄OH

Answer 1

NH₂^-

Question 2

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)

Answer 2

HNO₃ is the acid and its conjugate base is NO₃^-(aq),and F^- is the base and its conjugate acid is HF

Question 3

Which species is the conjugate acid of HPO₄^2-?

A)PO₄^3-
B)P₂O
C)H₂PO₄-
D)H₂O
E)OH^-

Answer 3

H₂PO₄-

Question 4

Which species can act as a Brønsted-Lowry acid?

A)CO₃^2-
B)HCl
C)Br₂
D)LiOH

Question 5

Correctly identify the conjugate acid-base pairs in the following equation: HC₂H₃O₂(l)+ H₂O(l) H₃O⁺(aq)+ C₂H₃O₂^-(aq)

A)HC₂H₃O₂/H₂O and H₂O/C₂H₃O₂^-
B)HC₂H₃O₂/H₂O and H₃O⁺/C₂H₃O₂^-
C)HC₂H₃O₂/ C₂H₃O₂^-and H₂O/ H₃O⁺
D)HC₂H₃O₂/ H₃O⁺ and H₂O/C₂H₃O₂^-

Question 6

Which species is the conjugate acid of HS^-?

A)H₂S
B)S^2-
C)HSO₂^-
D)H⁺

Question 7

Which species is a diprotic acid?

A)Mg(OH)₂
B)CH₃COOH
C)H₂
D)H₂CO₃

Question 8

Which species can act as an Arrhenius base?

A)CO₃^2-
B)HNO₃
C)LiOH
D)NH₃

Question 9

Which species is the conjugate acid of HCO₃^-?

A)CO₃^2-
B)H₂CO₃
C)CO₂
D)H₂O

Question 10

A Brønsted-Lowry base 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 11

Which species is the conjugate base of HCN?

A)H₂CN⁺
B)CN^-
C)H⁺
D)H₂O

Question 12

Which species can act as a Brønsted-Lowry base?

A)NO₃^-
B)HBr
C)H₂CO₃
D)NH₄⁺

Question 13

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 14

An Arrhenius base 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 15

Which species is the conjugate base of HPO₄^2-?

A)H₂PO₄^-
B)H₃PO₄
C)H₂O
D)PO₄^3-

Question 16

Correctly identify the missing product in the following acid-base reaction: NH₃ + HCl NH₄⁺ + ________

A)Cl^-
B)H₂Cl⁺
C)Cl₂
D)OH^-

Question 17

What is the correct name of HNO₂?

A)Nitrous acid
B)Nitric acid
C)Nitrate acid
D)Nitrite acid

Question 18

An Arrhenius acid is ________.

A)a compound that contains hydroxide and dissolves in water to form OH^-
B)a compound that is an electron 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 19

Which of the following is the hydronium ion?

A)H₂O
B)H₃O⁺
C)OH^-
D)H⁺

Question 20

What is the correct name of H₂SO₄?

A)Sulfate acid
B)Hydrogen sulfide acid
C)Sulfuric acid
D)Sulfurous acid

Question 21

Ammonia,NH₃,is an example of a ________.

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

Question 22

Which ion is the strongest base?

A)Br^-
B)F^-
C)I^-
D)NO₃^-

Question 23

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 24

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 25

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 26

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 27

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

A)NaOH(aq)+ HBr(aq)→ H₂O(l)+ NaBr(aq)
B)Na⁺(aq)+ ^-OH(aq)+ H⁺(aq)+ Br^-(aq)→ H₂O(l)+ Na⁺(aq)+ Br^-(aq)
C)Na⁺(aq)+ ^-OH(aq)+ H⁺(aq)+ Br^-(aq)→ H⁺(aq)+ ^-OH(aq)+ Na⁺(aq)+ Br^-(aq)
D).^-OH(aq)+ H⁺(aq)→ H₂O(l)

Question 28

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 29

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 30

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 31

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 32

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 33

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 34

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 35

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

Question 36

Which pH value indicates the higher concentration of OH^-?

A)pH = 3.7
B)pH = 10.2
C)pH = 8.8
D)pH = 6.9
E)pH = 11.4

Question 37

Which pH value indicates the higher concentration of H₃O⁺?

A)pH = 11.5
B)pH = 12.9
C)pH = 7.0
D)pH = 5.2
E)pH = 6.6

Question 38

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

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

Question 39

Which compound is a weak acid?

A)HNO₃
B)HBr
C)CH₃COOH
D)H₂SO₄

Question 40

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 41

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 42

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)→ 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 43

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

Question 44

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 45

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 46

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)0.15 M NaOH
E)1.0 M HCl

Question 47

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 48

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 49

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

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

Question 50

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 51

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 is a buffer.

Question 52

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 53

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 have the same pH.

Question 54

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

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 55

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

A)RbI
B)NaCH₃COO
C)LiNO₂
D)(NH₄)₂SO₄

Question 56

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)→ 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 57

Which salt forms a basic solution when dissolved in water?

A)KCl
B)NH₄Br
C)LiNO₃
D)Na₃PO₄

Question 58

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

Question 59

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 60

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

A)
B)
C)
D)

Question 61

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

Question 62

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 63

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

Question 64

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

Question 65

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 66

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

Question 67

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

Question 68

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

Question 69

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

Question 70

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 71

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

Question 72

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

Question 73

An aqueous solution of NaHCO₃ is basic.

Question 74

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

Question 75

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 76

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

Question 77

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

Question 78

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

Question 79

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

Question 80

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