Question 1

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X- is a weak base.

Accepted Answer

A) True 
 B)False

Question 2

When 14.7 mL of aqueous HBr (a strong acid)  was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

Accepted Answer

A)   1.9 × 10-3 M
B)   140 M
C)   0.288 M
D)   0.13 M
E)   None of these choices are correct.F) B) and E)
G) A) and E)

Question 3

What is the pH of a 0.0125 M NaOH solution?

Accepted Answer

A)   0.972
B)   1.903
C)   12.097
D)   13.028
E)   None of these choices are correct.F) All of the above
G) A) and B)

Question 4

What is the value of Kb for the formate anion, HCOO-? Ka(HCOOH)  = 2.1 × 10-4

Accepted Answer

A)   (-2.1 × 10-4) 
B)   2.1 × 10-4
C)   6.9 × 10-6
D)   4.8 × 10-11
E)   2.1 × 10-18F) C) and E)
G) A) and E)

Question 5

Farmers who raise cotton once used arsenic acid, H3AsO4, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K1 = 2.5 × 10-4, K2 = 5.6 × 10-8, and K3 = 3 × 10-13. What is the pH of a 0.500 M solution of arsenic acid?

Accepted Answer

A)   0.85
B)   1.96
C)   3.90
D)   4.51
E)   None of these choices are correct.F) B) and E)
G) A) and E)

Question 6

Given: H2O(aq)  + H2O(l)  2O(aq)  + H2O(l)    H3O+(aq)  + OH-(aq)  ΔH°rxn > 0 When the temperature of a sample of pure water is raised above 25°C, A)  the hydronium ion concentration will be greater than the hydroxide ion concentration. B)  the hydronium ion concentration will be less than the hydroxide ion concentration. C)  the value of Kw will increase. D)  the hydronium ion concentration could change to 1.0 × 10-10 M. E)  the hydroxide ion concentration could change to 1.0 × 10-10 M." class="answers-bank-image d-inline" rel="preload" > H3O+(aq)  + OH-(aq)  ΔH°rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

Accepted Answer

A)   the hydronium ion concentration will be greater than the hydroxide ion concentration.
B)   the hydronium ion concentration will be less than the hydroxide ion concentration.
C)   the value of Kw will increase.
D)   the hydronium ion concentration could change to 1.0 × 10-10 M.
E)   the hydroxide ion concentration could change to 1.0 × 10-10 M.F) B) and E)
G) A) and B)

Question 7

What is the [OH-] for a solution at 25°C that has [H3O+] = 2.35 × 10-3 M?

Accepted Answer

A)   4.26 × 10-5 M
B)   2.35 × 10-11 M
C)   4.26 × 10-12 M
D)   2.35 × 10-17 M
E)   None of these choices are correct.F) A) and B)
G) A) and C)

Question 8

A solution is prepared by adding 0.10 mol of sodium sulfide, Na2S, to 1.00 L of water. Which statement about the solution is correct?

Accepted Answer

A)   The solution is basic.
B)   The solution is neutral.
C)   The solution is acidic.
D)   The concentration of sodium ions and sulfide ions will be identical.
E)   The concentration of sulfide ions will be greater than the concentration of sodium ions.F) A) and E)
G) B) and E)

Question 9

Which, if any, of the following is an example of the leveling effect?

Accepted Answer

A)   The concentrations of H+ and OH- in pure water are equal.
B)   The number of strong acids equals the number of strong bases.
C)   The number of strong acids equals the number of weak acids.
D)   In water, no acid stronger than H3O+ can exist.
E)   None of these are examples of the leveling effect.F) All of the above
G) A) and B)

Question 10

What is the [H3O+] for a solution at 25°C that has pOH = 5.640?

Accepted Answer

A)   2.34 × 10-4 M
B)   2.29 × 10-6 M
C)   4.37 × 10-9 M
D)   4.27 × 10-11 M
E)   8.360 MF) A) and B)
G) A) and C)

Question 11

Select the pair of substances in that an acid is listed followed by its conjugate base.

Accepted Answer

A)   H+, HCl
B)   NH3, NH4+
C)   HPO42-, H2PO4-
D)   HCO3-, CO32-
E)   CH3COOH, CH3COOH2+F) None of the above
G) C) and D)

Question 12

The substance NaNO3 is considered

Accepted Answer

A)   a weak Arrhenius acid.
B)   a weak Arrhenius base.
C)   a strong Arrhenius acid.
D)   a strong Arrhenius base.
E)   a neutral compound.F) B) and C)
G) None of the above E

Question 13

What is the pH of a 0.0035 M KOH solution?

Accepted Answer

A)   2.46
B)   5.65
C)   8.35
D)   11.54
E)   None of these choices are correct.F) B) and D)
G) A) and C)

Question 14

All weak acids have strong conjugate bases.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following is the strongest acid?

Accepted Answer

A)   CH3COOH
B)   HF
C)   H3PO4
D)   H2SO3
E)   HIF) C) and D)
G) A) and B) E

Question 16

What is the [OH-] for a solution at 25°C that has pH = 4.29?

Accepted Answer

A)   1.4 × 10-2 M
B)   5.l × 10-5 M
C)   1.9 × 10-10 M
D)   7.3 × 10-13 M
E)   9.71 MF) All of the above
G) A) and C)

Question 17

Which of the following is considered a Lewis acid?

Accepted Answer

A)   CH3NH2
B)   BCl3
C)   F-
D)   BF4-
E)   CH4F) D) and E)
G) A) and E)

Question 18

The acid dissociation constant Ka equals 1.26 × 10-2 for HSO4- and is 5.6 × 10-10 for NH4. Which statement about the following equilibrium is correct? HSO4-(aq)  + NH3(aq)  a equals 1.26 × 10-2 for HSO4- and is 5.6 × 10-10 for NH4. Which statement about the following equilibrium is correct? HSO4-(aq)  + NH3(aq)    SO42-(aq)  + NH4+(aq)  A)  The reactants will be favored because ammonia is a stronger base than the sulfate anion. B)  The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion. C)  Neither reactants nor products will be favored because all of the species are weak acids or bases. D)  The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made. E)  This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation." class="answers-bank-image d-inline" rel="preload" > SO42-(aq)  + NH4+(aq)

Accepted Answer

A)   The reactants will be favored because ammonia is a stronger base than the sulfate anion.
B)   The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion.
C)   Neither reactants nor products will be favored because all of the species are weak acids or bases.
D)   The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made.
E)   This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation.F) B) and C)
G) A) and D)

Question 19

What is the pOH of a 0.0250 M HI solution?

Accepted Answer

A)   0.944
B)   1.602
C)   12.398
D)   13.056
E)   None of these choices are correct.F) A) and E)
G) All of the above C

Question 20

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Accepted Answer

A) True 
 B)False

Exam 18: Acid-Base Equilibria

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X- is a weak base.

Correct AnswerverifiedShow Answer

When 14.7 mL of aqueous HBr (a strong acid) was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

Correct AnswerverifiedShow Answer

What is the pH of a 0.0125 M NaOH solution?

Correct AnswerverifiedShow Answer

What is the value of Kb for the formate anion, HCOO-? Ka(HCOOH) = 2.1 × 10-4

Correct AnswerverifiedShow Answer

Farmers who raise cotton once used arsenic acid, H3AsO4, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K1 = 2.5 × 10-4, K2 = 5.6 × 10-8, and K3 = 3 × 10-13. What is the pH of a 0.500 M solution of arsenic acid?

Correct AnswerverifiedShow Answer

Given: H2O(aq) + H2O(l) H3O+(aq) + OH-(aq) ΔH°rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

Correct AnswerverifiedShow Answer

What is the [OH-] for a solution at 25°C that has [H3O+] = 2.35 × 10-3 M?

Correct AnswerverifiedShow Answer

A solution is prepared by adding 0.10 mol of sodium sulfide, Na2S, to 1.00 L of water. Which statement about the solution is correct?

Correct AnswerverifiedShow Answer

Which, if any, of the following is an example of the leveling effect?

Correct AnswerverifiedShow Answer

What is the [H3O+] for a solution at 25°C that has pOH = 5.640?

Correct AnswerverifiedShow Answer

Select the pair of substances in that an acid is listed followed by its conjugate base.

Correct AnswerverifiedShow Answer

The substance NaNO3 is considered

Correct AnswerverifiedE

What is the pH of a 0.0035 M KOH solution?

Correct AnswerverifiedShow Answer

All weak acids have strong conjugate bases.

Correct AnswerverifiedShow Answer

Which of the following is the strongest acid?

Correct AnswerverifiedE

What is the [OH-] for a solution at 25°C that has pH = 4.29?

Correct AnswerverifiedShow Answer

Which of the following is considered a Lewis acid?

Correct AnswerverifiedShow Answer

The acid dissociation constant Ka equals 1.26 × 10-2 for HSO4- and is 5.6 × 10-10 for NH4. Which statement about the following equilibrium is correct? HSO4-(aq) + NH3(aq) SO42-(aq) + NH4+(aq)

Correct AnswerverifiedShow Answer

What is the pOH of a 0.0250 M HI solution?

Correct AnswerverifiedC

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Correct AnswerverifiedShow Answer

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X^- is a weak base.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

What is the value of K_b for the formate anion, HCOO^-? K_a(HCOOH) = 2.1 × 10^-4

Correct Answer
verified

Farmers who raise cotton once used arsenic acid, H₃AsO₄, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K₁ = 2.5 × 10^-4, K₂ = 5.6 × 10^-8, and K₃ = 3 × 10^-13. What is the pH of a 0.500 M solution of arsenic acid?

Correct Answer
verified

Given: H₂O(aq) + H₂O(l) H₃O⁺(aq) + OH^-(aq) ΔH°_rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

Correct Answer
verified

What is the [OH-] for a solution at 25°C that has [H₃O⁺] = 2.35 × 10^-3 M?

Correct Answer
verified

A solution is prepared by adding 0.10 mol of sodium sulfide, Na₂S, to 1.00 L of water. Which statement about the solution is correct?

Correct Answer
verified

Correct Answer
verified

What is the [H₃O⁺] for a solution at 25°C that has pOH = 5.640?

Correct Answer
verified

Correct Answer
verified

The substance NaNO₃ is considered

Correct Answer
verified
E

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
E

What is the [OH^-] for a solution at 25°C that has pH = 4.29?

Correct Answer
verified

Correct Answer
verified

The acid dissociation constant K_a equals 1.26 × 10^-2 for HSO₄^- and is 5.6 × 10^-10 for NH₄. Which statement about the following equilibrium is correct? HSO_4-(aq) + NH₃(aq) SO₄^2-(aq) + NH₄⁺(aq)

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified