Chapter 14: Acid-Base Equilibria Flashcards by Amber Barnhart

According to the Brønsted-Lowry definition, what is an acid?
A) A substance that donates an OH⁻ ion
B) A substance that donates an H⁺ ion
C) A substance that accepts an H⁺ ion
D) A substance that produces H₂ gas in solution

B) A substance that donates an H⁺ ion

How well did you know this?

Not at all

Perfectly

Which of the following is a Brønsted-Lowry base?
A) HCl
B) NH₃
C) H₂SO₄
D) HBr

B) NH₃

How well did you know this?

Not at all

Perfectly

What are the products of a neutralization reaction?
A) A weak acid and a strong base
B) A strong acid and a weak base
C) A salt and water
D) A gas and a metal

C) A salt and water

How well did you know this?

Not at all

Perfectly

Which of the following is the correct net ionic equation for the neutralization of HCl and NaOH?

A) HCl + NaOH → NaCl + H₂O
B) H⁺ + OH⁻ → H₂O
C) Cl⁻ + Na⁺ → NaCl
D) H₃O⁺ + OH⁻ → NaCl

B) H⁺ + OH⁻ → H₂O

How well did you know this?

Not at all

Perfectly

What is the conjugate base of H₂CO₃?

A) H₃CO₃⁺
B) CO₃²⁻
C) HCO₃⁻
D) OH⁻

C) HCO₃⁻

How well did you know this?

Not at all

Perfectly

Which of the following represents a conjugate acid-base pair?

A) NH₃ and NH₄⁺
B) HCl and NaOH
C) H₂O and OH⁻
D) Both A and C

D) Both A and C

How well did you know this?

Not at all

Perfectly

In the following reaction, what is the conjugate acid of NH₃?
NH3+H2O⇌NH4+OH-

A) NH₂⁻
B) NH₄⁺
C) OH⁻
D) H₃O⁺

B) NH₄⁺

How well did you know this?

Not at all

Perfectly

What is true about H₃O⁺ and H⁺?

A) They are completely different molecules.
B) H₃O⁺ is the hydrated form of H⁺.
C) H₃O⁺ is a strong base.
D) H⁺ is a spectator ion in all acid-base reactions.

B) H₃O⁺ is the hydrated form of H⁺.

How well did you know this?

Not at all

Perfectly

Which of the following statements about water is true?

A) Water is only a base.
B) Water is only an acid.
C) Water can act as both an acid and a base and is amphiprotic
D) Water is neither an acid nor a base and is amphiprotic

C) Water can act as both an acid and a base and is amphiprotic

How well did you know this?

Not at all

Perfectly

What is the autoionization of water?

A) The dissociation of an acid in solution
B) The formation of H₃O⁺ from H₂O
C) The reaction of water with itself to produce H₃O⁺ and OH⁻
D) The neutralization of a base by an acid

C) The reaction of water with itself to produce H₃O⁺ and OH⁻

How well did you know this?

Not at all

Perfectly

What is the hydronium ion concentration in pure water at 25°C?
A) 1.0×10 ^−7M
B) 1.0×10 ^−14M
C) 1.0M
D) 7.0 M

A) 1.0×10 ^−7M

How well did you know this?

Not at all

Perfectly

What is the value of 𝐾𝑤 at 25°C?

A) 1.0×10 ^−7M
B) 1.0×10 ^−14M
C) 1.0M
D) 7.0 M

B) 1.0×10 ^−14M

How well did you know this?

Not at all

Perfectly

What happens when [H₃O⁺] > [OH⁻]?
A) The solution is acidic.
B) The solution is neutral.
C) The solution is basic.
D) The reaction stops.

A) The solution is acidic.

How well did you know this?

Not at all

Perfectly

Which of the following is a strong acid?

A) HF
B) HNO₂
C) H₂SO₄
D) CH₃COOH

C) H₂SO₄

H₂SO₄ (sulfuric acid) is one of the 6 strong acids that completely dissociate in water.

How well did you know this?

Not at all

Perfectly

What happens when [H₃O⁺] = [OH⁻]?
A) The solution is acidic.
B) The solution is basic.
C) The solution is neutral.
D) The reaction stops.

C) The solution is neutral.

How well did you know this?

Not at all

Perfectly

What happens when [H₃O⁺] < [OH⁻]?
A) The solution is acidic.
B) The solution is neutral.
C) The solution is basic.
D) The reaction stops.

C) The solution is basic.

How well did you know this?

Not at all

Perfectly

Which of the following is NOT a strong acid?
A) HBr
B) HClO₃
C) HF
D) HCl

C) HF

Hydrofluoric acid (HF) is a weak acid because it only partially dissociates in water.

How well did you know this?

Not at all

Perfectly

Which of the following is NOT a strong base?
A) NaOH
B) Ba(OH)₂
C) NH₃
D) KOH

C) NH₃

Explanation: Ammonia (NH₃) is a weak base because it partially accepts H⁺ in solution.

How well did you know this?

Not at all

Perfectly

Which of the following is a strong acid?
A) HNO₂
B) H₃PO₄
C) H₂SO₄
D) CH₃COOH

C) H₂SO₄

Explanation: Sulfuric acid (H₂SO₄) is a strong acid because it fully dissociates in water.

How well did you know this?

Not at all

Perfectly

Which of the following is a strong base?
A) Ca(OH)₂
B) NH₄OH
C) H₂O
D) HNO₃

A) Ca(OH)₂

Explanation: Calcium hydroxide (Ca(OH)₂) is a strong base because it completely dissociates in water.

How well did you know this?

Not at all

Perfectly

Which of the following is a strong acid?
A) HNO₃
B) HCOOH
C) H₂CO₃
D) HF

A) HNO₃

How well did you know this?

Not at all

Perfectly

Which of the following is a strong base?
A) LiOH
B) NH₃
C) H₂O
D) H₂SO₄

A) LiOH

How well did you know this?

Not at all

Perfectly

Which of the following is NOT a strong acid?
A) HClO₄
B) HBr
C) H₃PO₄
D) HI

C) H₃PO₄

How well did you know this?

Not at all

Perfectly

Which of the following is a strong base?
A) NaOH
B) CH₃OH
C) HCl
D) NH₃

A) NaOH

How well did you know this?

Not at all

Perfectly

Which of the following is a strong acid? A) H₂CO₃ B) CH₃COOH C) HClO₄ D) HNO₂

C) HClO₄

Which of the following is a strong base? A) NH₃ B) RbOH C) HF D) HNO₃

B) RbOH

What is true about the pH of an acidic solution? a.) [H3O+] < [OH-] and pH >7 b.) [H3O+] = [OH-] and pH =7 c.) [H3O+] > [OH-] and pH <7 d.) [H3O+] > [OH-] and pH >7

c.) [H3O+] > [OH-] and pH <7

What is the hydroxide ion concentration in a solution where [H3O+]=2.0*10^-6M at 25C? a.) 5.0*10^-9M b.) 1.0*10^-14M c.) 2.0*10^-6M d.) 1.0*10^-8M

a.) 5.0*10^-9M 1.0*10^-12/2/0*10^-6

What is the pH of a solution of stomach acid with [H3O+] = 1.2*10^-3M? a.) 2.92 b.) 11.08 c.) 5.00 d.) 7.00

a.) 2.92 -log(1.2*10^-3)

What is the pOH of the stomach acid solution from [H3O+] = 1.2*10^-3M? A) 2.92 B) 5.00 C) 11.08 D) 7.00

C) 11.08 -log(1.2*10^-3)=2.92 14-2.92 = 11.08

What is the hydroxide ion concentration in the stomach acid solution where [H3O+] = 1.2*10^-3M? a.) 8.3*10^-12M b.) 1.0*10^-14M c.) 2.0*10^-6M d.) 5.0*10^-9

a.) 8.3*10^-12M 1.0*10^-14M/1.2*10^-3M

Which of the following is NOT a strong acid? A) HClO₄ B) HCl C) HF D) HNO₃

C) HF

Which of the following is NOT a strong base? A) NaOH B) Ba(OH)₂ C) NH₃ D) KOH

C) NH₃

What is the conjugate acid of NO₂⁻? A) HNO₂ B) NO₃⁻ C) NH₄⁺ D) HNO₃

A) HNO₂

What is the Ka for HNO₂ if the Kb of NO₂⁻ is 2.17*10^-11? a.) 4.6*10^-4 b.) 1.0*10^-14 c.) 2.17*10^-11 d.) 3.2*10^-3

a.) 4.6*10^-4 Ka*Kb=Kw 1.00*10^-14/2.17*10^-11 = 4.6*10^-4

What is the percent ionization of a 0.125𝑀 solution of nitrous acid (NHO2) with a pH of 2.09? A) 6.5% B) 1.2% C) 9.8% D) 4.3%

A) 6.5% [H3O+]=10^-pH = 10^-2.09 = 0.0081M [H3O+]/[HA]*100 = 0.0081/0.125*100 = 6.5%

Which of the following is true about strong acids and bases? A) Strong acids have weak conjugate bases. B) Strong bases have weak conjugate acids. C) Both A and B. D) Neither A nor B.

C) Both A and B.

What is the Ka value for acetic acid if at equilibrium: [CH₃COOH] = 0.0787 M [CH₃COO⁻] = [H₃O⁺] = 0.00118 M a.) 1.17*10^-5 b.) 3.21*10^-4 c.) 5.01*10^-3 d.) 7.12*10^-6

a.) 1.17*10^-5 Ka=[CH3COO-][H3O]/CH3COOH] = (0.00118)(0.00118)/0.0787 = 1/17*10^-5

In an aqueous solution at 25 °C, if [H₃O⁺] = 9.1 × 10⁻⁴ M, then [OH⁻] is:

1.1*10^-11M 1.0*10^-14/9.1*10^-4

Ba(OH)₂ is a Brønsted-Lowry base because a.) it is a polar molecule b.) it is a hydroxide donor c.) it is a proton acceptor d.) it can dissolve water

c.) it is a proton acceptor

Consider the following reaction in the forward direction. Identify the acid: CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻ a.) CH3O- b.) H2O c.) CH3OH d.) OH-

b.) H2O

Consider the following reaction in the forward direction. Identify the base: CH₃CH₂OH + HCl ⇌ CH₃CH₂OH₂⁺ + Cl⁻ a.) CH3CH2OH b.) HCl c.) Ch3Ch2OH2+ d.) Cl-

a.) CH3CH2OH

Consider the following reaction in the forward direction. Identify the conjugate acid: CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻ a.) CH3O- b.) H2O c.) CH3OH d.) OH-

c.) CH3OH

The OH⁻ concentration in an aqueous solution at 25 °C is 5.3 × 10⁻³ M. What is [H⁺]?

1.9 × 10⁻¹² M 1.0*10^-14/5.3*10^-3

Consider the following reaction in the forward direction. Identify the conjugate base: CH₃O⁻ + H₂O ⇌ CH₃OH + OH⁻ a.) CH3O- b.) H2O c.) CH3OH d.) OH-

d.) OH-

HBr is an Arrhenius acid because a.) it produces hydronium ions in a solution b.) it produces hydroxide ions in a solution. c.) it is a polar molecule d.) it can dissolve in water

a.) it produces hydronium ions in a solution

Predict the conjugate acid of C₅H₅N. a.) C5H5N- b.) C5H5NH+ c.) C5H5NH2+ d.) C5H5NH

b.) C5H5NH+ C₅H₅NH⁺. A Bronsted-Lowry base such as pyridine (C₅H₅N) will accept a proton (H⁺) to form its conjugate acid, pyridinium (C₅H₅NH⁺).

Predict the conjugate base of CF₃CO₂H. a.) CF3CO2H2+ b.) CF3CO2- c.) CF3CO2+ d.) CF3CO-

b.) CF3CO2- CF₃CO₂⁻. A Bronsted-Lowry acid such as trifluoroacetic acid (CF₃CO₂H) will lose the acidic proton (H⁺) attached to the oxygen atom to form its negatively charged conjugate base, trifluoroacetate (CF₃CO₂⁻).

Which acid-base definition classifies an acid as an electron-pair acceptor? a.) Arrhenius b.) Bronsted-Lowry c.) Lewis

c.) Lewis

Which of the following is a conjugate acid-base pair? a.) H3PO3, H2PO3- b.) H2PO3-, PO33- c.) H3PO3, PO33- d.) H3PO3, HPO32-

a.) H3PO3, H2PO3-

Which of the following is an amphoteric species? a.) H2CO3 b.) HCO3- c.) CO32-

b.) HCO3- An amphoteric species can be an acid or a base. When this species acts as an acid in water it donates a proton: When this species acts as a base in water it accepts a proton:

A solution has a pH of 7.6. What does that say about the solution? a.) the solution is slightly acidic. b.) the solution is slightly basic. c.) the solution is neutral. d.) the solution is highly acidic.

b.) the solution is slightly basic.

What is the pH of a 0.0000755 M solution of CsOH?

9.88 -log(0.0000755) = 4.12 14-4.12

What is the pH of a 0.000680 M solution of HBr?

3.17 -log(0.000680) (remember to only subtract from 14 when solving for a base)

A solution has a pH of 1.75. We can conclude that a.) the solution is very acidic. b.) the solution is only slightly acidic. c.) the solution is only slightly basic. d.) the solution is very basic.

a.) the solution is very acidic.

A solution has a pOH of 1.47. This tells us a.) the solution is very acidic. b.) the solution is only slightly acidic. c.) the solution is only slightly basic. d.) the solution is very basic.

d.) the solution is very basic.

The pH of a basic solution is 10.45. What is [H⁺]?

3.5 × 10⁻¹¹ M 10^-pH or 10^-10.45

The pOH of an acidic solution is 10.29. What is [OH⁻]?

5.1 × 10⁻¹¹ M 10^-19.29

The OH⁻ concentration in a solution of C₅H₅N is 3.4 × 10⁻⁵ M at 25 °C. What is the pH of this solution?

9.53 -log(2.4*10^-5) = 4.47 = pOH 14-4.47

The pOH of a solution is 9.50. What is the H⁺ concentration in the solution?

3.2 × 10⁻⁵ M 14-9.5 = 4.5 = pH 10^-4.5 = H+ concentration

Which one of the following correctly shows the equilibrium for the weak base quinoline, C₉H₇N? a.) C9H7N(aq) + 2H2O(l) ⇌ C9H7NH2+(aq) + 2OH-(aq) b.) C0H7N(aq) + H2O(l) ⇌ C9H7NH+(aq) + OH-(aq) c.) C9H7N(aq) + H2O ⇌ C9H6N(aq) + H3O+(aq) d.) C9H7N(aq) + H2O(l) ⇌ C9H8NO(aq) + H3O+(aq)

b.) C0H7N(aq) + H2O(l) ⇌ C9H7NH+(aq) + OH-(aq)

Which one of the following correctly shows the weak acid equilibrium for trichloroacetic acid, CCl₃COOH? a.) CCL3COOH(aq) ⇌ CCl3CO+(aq) + OH-(aq) b.) CCl3COOH(aq) + H2O ⇌ CCl3COOH2+(aq) +OH-(aq) c.) CCl3COOH(aq) +H2O(l) ⇌ CCl3COO-(aq) + H3O+(aq) d.) CCl3CHOOH(aq) + H2O(l) ⇌ CCl3CO(OH)2-(aq) + H+(aq)

c.) CCl3COOH(aq) +H2O(l) ⇌ CCl3COO-(aq) + H3O+(aq)

What is Ka for the conjugate acid of H₂NNH₂ (Kb = 1.3 × 10⁻⁶)?

7.7 × 10⁻⁹ Kw/Kb or 10*10^-14/1.3*10^-6

HI is considered an acid because a.) it is a polar molecule b.) it can dissolve in water c.) it produces hydronium ions in solution. d.) it produces hydroxide ions in solution.

d.) it produces hydroxide ions in solution.

Which of the following will be the strongest acid? a.) HIO b.) HIO2 c.) HIO3 d.) HIO4

d.) HIO4 The more electronegative oxygen atoms there are, the higher the acid strength. Out of this list, HIO4 contains the greatest number of electronegative oxygen atoms.

Which one of the following correctly shows the weak acid equilibrium for nitrous acid, HNO₂? a.) HNO2(aq) ⇌ NO+(aq) + OH-(aq) b.) HNO2(aq) + H2O(l) ⇌ NO2-(aq) + H3O+(aq) c.) HNO2(aq) + H2O(l) ⇌ N2NO3-(aq) + H+(aq) d.) HNO2(aq) + H2O(l) ⇌ N2NO2+(aq) + OH-(aq)

b.) HNO2(aq) + H2O(l) ⇌ NO2-(aq) + H3O+(aq)

What is the equilibrium constant, K, for the reaction between HCN (Ka = 6.2 x 10⁻¹⁰) and OH⁻ at 25 °C?

6.2 × 10⁴ (1.0*10^-14)*(6.2*10-10)

An unknown weak acid with a concentration of 0.056 M has a pH of 1.80. What is the Ka of the weak acid?

6.26 × 10⁻³ 10^-1.8 H+=1.58*10^-2 ICE TABLE Initial Change Equilib HA 0.090 -x 0.090-x H+ 0 +x x A- 0 +x x Ka= [H+][A-]/[HA] [(1.58*10^-2)(1.58*10^-2)]/0.090-1.58*10^-2

An unknown weak base with a concentration of 0.0910 M has a pH of 10.40. What is the Kb of this base?

7.0 × 10⁻⁷ pOH = 14 - 11.70 = 2.30 10^-2.30 = 5.01*10^-3 kb = [(5.01*10^-3)(5.01*10^-3)]/[0.0910-5.011*10^-3)]

What is [H⁺] in a 0.500 M solution of acrylic acid, CH₂CHCOOH (Ka = 3.16 × 10⁻⁵)?

3.97 × 10⁻³ 3.16*10^-5=[x][x]/0.270-x x^2=8.532*10^-6 x=2.92*10^-3 ([8.532*10^-6/0.270) *100%

What is the [OH⁻] of a 1.70 M solution of pyridine (C₅H₅N, Kb = 1.70 × 10⁻⁹)?

5.38 × 10⁻⁵ M

What is the pH of a 0.0670 M solution of methylamine (CH₃NH₂, Kb = 4.4 × 10⁻⁴)?

11.72 4.4*10^-4=[x][x]/[0.0670-x] take -log of answer subtract from 14

What is the pH of a 0.0690 M solution of hydrocyanic acid, HCN (Ka = 4.9 × 10⁻¹⁰)?

5.24

What is the percent ionization in a 0.520 M solution of formic acid (HCOOH) (Ka = 1.78 × 10⁻⁴)?

1.83% 1.78*10^-4=[x][x]/[0.520] divide value by 0.520 *100%

Which of the following reactions accurately shows how Fe³⁺ acts as an acid in water? a.) Fe(OH)3(s) ⇌ Fe3+(aq) +3OH-(aq) b.) Fe3+(aq) + 5H2O(l) ⇌ Fe(h2O)53+(aq) c.) Fe(H2O)63+(aq) + 3OH-(aq) ⇌ Fe(H2O)5(OH)2+(aq) +H+(aq) d.) Fe3+(aq) + 3OH-(aq) ⇌ Fe(OH)3(s)

c.) Fe(H2O)63+(aq) + 3OH-(aq) ⇌ Fe(H2O)5(OH)2+(aq) +H+(aq)