Question 1

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.

Question 2

The substance H2SO3 is considered

Accepted Answer

A)   a weak Arrhenius base.
B)   a strong Arrhenius acid.
C)   a strong Arrhenius base.
D)   a neutral compound.
E)   a weak Arrhenius acid.

Question 3

What is the [OH-] for a solution at 25°C that has [H3O+] = 8.23 × 10-2 M?

Accepted Answer

A)   > 10-5 M
B)   1.22 × 10-6 M
C)   8.23 × 10-12 M
D)   1.22 × 10-13 M
E)   8.23 × 10-16 M

Question 4

Which one of the following substances will give an aqueous solution of pH closest to 7?

Accepted Answer

A)   KNO3
B)   CO2
C)   NH4I
D)   NH3
E)   CH3NH2

Question 5

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.

Question 6

Arsenic acid, H3AsO4, is used industrially to manufacture insecticides. 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 concentration of the HAsO42- in a solution whose initial arsenic acid concentration was 0.35 M?

Accepted Answer

A)   9.4 × 10-3 M
B)   2.5 × 10-4 M
C)   8.8 × 10-5 M
D)   5.6 × 10-8 M
E)   none of the above

Question 7

Formic acid, which is a component of insect venom, has a Ka = 1.8 × 10-4. What is the [H3O+] in a solution that is initially 0.10 M formic acid, HCOOH?

Accepted Answer

A)   4.2 × 10-3 M
B)   8.4 × 10-3 M
C)   1.8 × 10-4 M
D)   1.8 × 10-5 M
E)   1.8 × 10-6 M

Question 8

What is the value of Ka for the methylammonium ion, CH3NH3+? Kb(CH3NH2)  = 4.4 × 10-4

Accepted Answer

A)   4.4 × 10-4
B)   4.8 × 10-6
C)   4.4 × 10-10
D)   2.3 × 10-11
E)   4.4 × 10-18

Question 9

Which, if any, of the following acids is strong?

Accepted Answer

A)   phosphoric
B)   carbonic
C)   acetic
D)   water
E)   none of the above

Question 10

Which one of the following will give a solution with a pH > 7, but is not an Arrhenius base in the strict sense?

Accepted Answer

A)   CH3NH2
B)   NaOH
C)   CO2
D)   Ca(OH) 2
E)   CH4

Question 11

Calcium oxide, CaO, also known as quick lime, will react with carbon dioxide to form calcium carbonate, CaCO3. Which species, if any, acts as a Lewis acid in the reaction?

Accepted Answer

A)   Ca2+
B)   O2-
C)   CO2
D)   CaCO3
E)   None of the species acts as a Lewis acid in this reaction.

Question 12

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 × 10-18

Question 13

The substance Ba(OH) 2 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. D

Question 14

(a) Write a balanced equation representing the reaction of the acid, H2PO4- with the base, water.
(b) Write the expression for Ka of H2PO4- in terms of concentrations of relevant species.

Accepted Answer

(a) H₂PO₄^-(aq...

Question 15

The substance HClO4 is considered

Accepted Answer

A)   a weak acid.
B)   a weak base.
C)   a strong acid.
D)   a strong base.
E)   a neutral compound. C

Question 16

According to Brønsted and Lowry, which one of the following is not a conjugate acid-base pair?

Accepted Answer

A)   H3O+/OH-
B)   CH3OH2+/CH3OH
C)   HI/I-
D)   HSO4-/SO42-
E)   H2/H-

Question 17

Which one of the following pairs is not a conjugate acid-base pair?

Accepted Answer

A)   H2O/OH-
B)   H2O2/HO2-
C)   OH-/O2-
D)   H2PO4-/HPO42-
E)   HCl/H+

Question 18

What is the pH of a 0.050 M triethylamine, (C2H5) 3N, solution? Kb for triethylamine is 5.3 × 10-4.

Accepted Answer

A)   11.69
B)   8.68
C)   5.32
D)   2.31
E)   < 2.0 A

Question 19

An aqueous solution is considered to be acidic if

Accepted Answer

A)   the hydroxide ion concentration is 10-6 M.
B)   the hydrogen ion concentration is 10-8 M.
C)   the hydroxide and hydrogen ion concentrations are equal.
D)   the hydroxide ion concentration is greater than the hydrogen ion concentration.
E)   the hydroxide ion concentration is 10-10 M.

Question 20

A 0.15 M solution of chloroacetic acid has a pH of 1.86. What is the value of Ka for this acid?

Accepted Answer

A)   7.2 × 101
B)   0.16
C)   0.099
D)   0.0014
E)   0.00027

Exam 18: Acid-Base Equilibria

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

The substance H2SO3 is considered

Correct AnswerverifiedShow Answer

What is the [OH-] for a solution at 25°C that has [H3O+] = 8.23 × 10-2 M?

Correct AnswerverifiedShow Answer

Which one of the following substances will give an aqueous solution of pH closest to 7?

Correct AnswerverifiedShow Answer

The substance NaNO3 is considered

Correct AnswerverifiedShow Answer

Arsenic acid, H3AsO4, is used industrially to manufacture insecticides. 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 concentration of the HAsO42- in a solution whose initial arsenic acid concentration was 0.35 M?

Correct AnswerverifiedShow Answer

Formic acid, which is a component of insect venom, has a Ka = 1.8 × 10-4. What is the [H3O+] in a solution that is initially 0.10 M formic acid, HCOOH?

Correct AnswerverifiedShow Answer

What is the value of Ka for the methylammonium ion, CH3NH3+? Kb(CH3NH2) = 4.4 × 10-4

Correct AnswerverifiedShow Answer

Which, if any, of the following acids is strong?

Correct AnswerverifiedShow Answer

Which one of the following will give a solution with a pH > 7, but is not an Arrhenius base in the strict sense?

Correct AnswerverifiedShow Answer

Calcium oxide, CaO, also known as quick lime, will react with carbon dioxide to form calcium carbonate, CaCO3. Which species, if any, acts as a Lewis acid in the reaction?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The substance Ba(OH) 2 is considered

Correct AnswerverifiedD

(a) Write a balanced equation representing the reaction of the acid, H2PO4- with the base, water. (b) Write the expression for Ka of H2PO4- in terms of concentrations of relevant species.

Correct Answerverified(a) H2PO4-(aq...View AnswerShow Answer

The substance HClO4 is considered

Correct AnswerverifiedC

According to Brønsted and Lowry, which one of the following is not a conjugate acid-base pair?

Correct AnswerverifiedShow Answer

Which one of the following pairs is not a conjugate acid-base pair?

Correct AnswerverifiedShow Answer

What is the pH of a 0.050 M triethylamine, (C2H5) 3N, solution? Kb for triethylamine is 5.3 × 10-4.

Correct AnswerverifiedA

An aqueous solution is considered to be acidic if

Correct AnswerverifiedShow Answer

A 0.15 M solution of chloroacetic acid has a pH of 1.86. What is the value of Ka for this acid?

Correct AnswerverifiedShow Answer

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

Correct Answer
verified

The substance H₂SO₃is considered

Correct Answer
verified

What is the [OH^-] for a solution at 25°C that has [H₃O⁺] = 8.23 × 10^-2M?

Correct Answer
verified

Correct Answer
verified

The substance NaNO₃is considered

Correct Answer
verified

Arsenic acid, H₃AsO₄, is used industrially to manufacture insecticides. 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 concentration of the HAsO₄^2- in a solution whose initial arsenic acid concentration was 0.35 M?

Correct Answer
verified

Formic acid, which is a component of insect venom, has a K_a = 1.8 × 10^-4. What is the [H₃O⁺] in a solution that is initially 0.10 M formic acid, HCOOH?

Correct Answer
verified

What is the value of K_a for the methylammonium ion, CH₃NH₃⁺? K_b(CH₃NH₂) = 4.4 × 10^-4

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Calcium oxide, CaO, also known as quick lime, will react with carbon dioxide to form calcium carbonate, CaCO₃. Which species, if any, acts as a Lewis acid in the reaction?

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

The substance Ba(OH) ₂is considered

Correct Answer
verified
D

(a) Write a balanced equation representing the reaction of the acid, H₂PO₄^- with the base, water. (b) Write the expression for K_a of H₂PO₄^- in terms of concentrations of relevant species.

Correct Answer
verified
(a) H₂PO₄^-(aq...
View Answer

The substance HClO₄is considered

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

What is the pH of a 0.050 M triethylamine, (C₂H₅) ₃N, solution? K_b for triethylamine is 5.3 × 10^-4.

Correct Answer
verified
A

Correct Answer
verified

A 0.15 M solution of chloroacetic acid has a pH of 1.86. What is the value of K_a for this acid?

Correct Answer
verified