Question 1

When [H⁺] = 1.0*10^-⁷ M in water at 25°C, then __________

Accepted Answer

In pure water at 25°C, [H⁺] = [OH^-] = 1.0 × 10^-7 M due to the autoionization of water.

Question 2

Ammonia (NH₃) acts as a weak base in aqueous solution. What is the acid that reacts with this base when ammonia is dissolved in water?

Accepted Answer

When ammonia (NH3) is dissolved in water, it accepts a proton (H+) to form the ammonium ion (NH4+). The acid that donates this proton is H₂O, which is the conjugate acid of the hydroxide ion (OH-). Therefore, the correct answer is choice B.

Question 3

Which of these is a strong acid that ionizes to make a weak acid?

Accepted Answer

B

Question 4

In the following reaction in aqueous solution, the acid reactant is __________, and its conjugate base product is __________. CH₃NH₂ + HSO₄^- CH₃NH₃⁺ + SO₄²^-

Accepted Answer

The answer of In the following reaction in aqueous solution,...

Question 5

In the Brønsted-Lowry definition of acids and bases, a base __________

Accepted Answer

According to the Brønsted-Lowry definition, a base is a proton acceptor.

Question 6

In the following reaction in aqueous solution, the acid reactant is __________ and its conjugate base product is __________. CH₃COOH + NH₃ CH₃COO^- + NH₄⁺

Accepted Answer

In the given reaction, CH₃COOH is the acid reactant as it donates a proton (H+) to NH₃ to form the conjugate base CH₃COO^-. Therefore, the acid reactant is CH₃COOH and its conjugate base product is CH₃COO^-.

Question 7

The degree of ionization of a weak acid __________
(I) varies with the concentration of the acid.
(II) depends on which weak acid it is.
(III) is 100%.
(IV) is greater than 50% but less than 100%.

Accepted Answer

The degree of ionization of a weak acid, by definition, is less than 100%. Therefore, options (III) and (IV) can be eliminated.

Option (I) is correct because the degree of ionization of a weak acid depends on its concentration. As the concentration of the weak acid increases, the degree of ionization increases as well. This is because a higher concentration of the weak acid means there are more molecules available to ionize.

Option (II) is also correct because the degree of ionization of a weak acid depends on its acid dissociation constant (Ka). Each weak acid has its own Ka value, and therefore, its own degree of ionization. Weak acids with larger Ka values will have a higher degree of ionization than weak acids with smaller Ka values.

Question 8

A solution with pH of 9.50 has a pOH of __________

Accepted Answer

The pH and pOH of a solution are related by the equation: pH + pOH = 14. Therefore, if the pH is 9.50, the pOH is 14 - 9.50 = 4.50.

Question 9

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

Accepted Answer

The answer of The base ionization constant K_b describes which...

Question 10

The degree of ionization of a strong acid is __________

Accepted Answer

A strong acid is completely ionized in water, so the degree of ionization is 100%. It does not depend on concentration or the specific strong acid.

Question 11

Which one, A-D, is not related to the water autoionization constant, K_w? If all are related, respond E.

Accepted Answer

The answer of Which one, A-D, is not related to...

Question 12

The acid ionization equilibrium constant, K_a, describes the reaction (where HA is a generic weak acid):

Accepted Answer

The acid ionization equilibrium constant, K_a, for a weak acid HA is given by the equation: HA + H2O ⇌ H3O+ + A-, where A is the conjugate base of the acid HA. The equilibrium constant expression for this reaction is: K_a = [H3O+][A-]/[HA] Option B is the only choice containing the above reaction and the corresponding equilibrium constant expression, and hence it is the correct answer.

Question 13

Which sketch best represents the qualitative molecular view of an aqueous solution of nitric acid? (Water molecules are not shown explicitly.)

Accepted Answer

The answer of Which sketch best represents the qualitative molecular...

Question 14

In the Brønsted-Lowry definition of acids and bases, an acid __________

Accepted Answer

According to the Brønsted-Lowry definition, an acid is a molecule or ion that donates a proton (H+) to another molecule or ion.

Question 15

Which statement about nitrous acid and nitric acid is correct?

Accepted Answer

The answer of Which statement about nitrous acid and nitric...

Question 16

A solution with a pOH of 6.92 has an [OH^-] concentration of __________

Accepted Answer

The answer of A solution with a pOH of 6.92...

Question 17

When [H⁺] = 4.0 *10^-⁹ M in water at 25°C, then __________

Accepted Answer

This is a question involving the calculation of the pH of a solution using the acid dissociation constant (Ka) of a weak acid.

The equation given is: 
[HS1U1P1+S1S1P0] = 4.0 F1F1F1S1F1F1F10 10S1U1P1-S1S1P0S1U1P19S1S1P0 M

This can be simplified as: 
[HS1U1P1] / [S1S1P0] = 4.0 F1F1F1S1F1F1F10 10S1U1P1-S1S1P0S1U1P19S1S1P0

Let x be the concentration of H+ ions produced from the dissociation of HS1U1P1.

Then, [HS1U1P1] = [S1S1P0] - x

Substituting this into the simplified equation above:

([S1S1P0] - x) / [S1S1P0] = 4.0 F1F1F1S1F1F1F10 10S1U1P1-S1S1P0S1U1P19S1S1P0

Multiplying both sides by [S1S1P0]:

[S1S1P0] - x = 4.0 F1F1F1S1F1F1F10 10S1U1P1 [S1S1P0] - 4.0 F1F1F1S1F1F1F10 10S1U1P1[S1S1P0]

Solving for x: 
x = Ka[HS1U1P1]

where Ka = 4.0 F1F1F1S1F1F1F10 10S1U1P1

Substituting the expression for [HS1U1P1]:

x = Ka([S1S1P0] - x)

Expanding and rearranging:

x2 + Ka x - Ka[S1S1P0] = 0

Solving for x using the quadratic formula:

x = [-Ka ± sqrt((Ka)2 + 4Ka[S1S1P0])] / 2

Taking the negative root (since H+ ions are produced by the dissociation of the weak acid):

x = [-Ka - sqrt((Ka)2 + 4Ka[S1S1P0])] / 2

Substituting the values for Ka and [S1S1P0]: 
x = [-4.0 F1F1F1S1F1F1F10 10S1U1P1 - sqrt((4.0 F1F1F1S1F1F1F10 10S1U1P1)2 + 4(4.0 F1F1F1S1F1F1F10 10S1U1P1)(S1U1P19S1S1P0))] / 2

Simplifying: 
x = (-4.0 F1F1F1S1F1F1F10 10S1U1P1 - 2.0 F1F1F1S1F1F1F10 10S1U1P1) / 2 
x = -3.0 F1F1F1S1F1F1F10 10S1U1P1

Finally, the pH can be calculated as: 
pH = -log[H+]

pH = -log(-3.0 F1F1F1S1F1F1F10 10S1U1P1)

pH = 8.40

Therefore, the answer is D) pH = 8.40.

Question 18

Which sketch best represents the qualitative molecular view of an aqueous solution of nitrous acid? (Water molecules are not shown explicitly.)

Accepted Answer

Sketch B shows the qualitative molecular view of an aqueous solution of nitrous acid, where the nitrous acid molecules partially dissociate into hydronium ions (H3O+) and nitrite ions (NO2-). This is consistent with the chemical equation for the dissociation of nitrous acid in water: HNO2 + H2O ⇌ H3O+ + NO2-. Sketches A, C, and D do not represent the dissociation of nitrous acid in water.

Question 19

When pure water autoionizes, the following species are produced: __________

Accepted Answer

When water autoionizes, it forms a hydronium ion (H3O+) and a hydroxide ion (OH-). Therefore, options A, C, and E can be immediately eliminated as they contain species that do not correspond to the autoionization of water. The only choice that includes both hydronium and hydroxide ions is B.

Question 20

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

Accepted Answer

Carbon dioxide reacts with water to form carbonic acid, which makes rainwater more acidic. This is known as acid rain.

Quiz 17: Equilibrium in the Aqueous Phase

When [H⁺] = 1.0*10^-⁷ M in water at 25°C, then __________

Ammonia (NH₃) acts as a weak base in aqueous solution. What is the acid that reacts with this base when ammonia is dissolved in water?

Which of these is a strong acid that ionizes to make a weak acid?

In the following reaction in aqueous solution, the acid reactant is , and its conjugate base product is . CH₃NH₂ + HSO₄^- CH₃NH₃⁺ + SO₄²^-

In the Brønsted-Lowry definition of acids and bases, a base __________

In the following reaction in aqueous solution, the acid reactant is and its conjugate base product is . CH₃COOH + NH₃ CH₃COO^- + NH₄⁺

The degree of ionization of a weak acid __________ (I) varies with the concentration of the acid. (II) depends on which weak acid it is. (III) is 100%. (IV) is greater than 50% but less than 100%.

A solution with pH of 9.50 has a pOH of __________

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

The degree of ionization of a strong acid is __________

Which one, A-D, is not related to the water autoionization constant, K_w? If all are related, respond E.

The acid ionization equilibrium constant, K_a, describes the reaction (where HA is a generic weak acid) :

Which sketch best represents the qualitative molecular view of an aqueous solution of nitric acid? (Water molecules are not shown explicitly.)

In the Brønsted-Lowry definition of acids and bases, an acid __________

Which statement about nitrous acid and nitric acid is correct?

A solution with a pOH of 6.92 has an [OH^-] concentration of __________

When [H⁺] = 4.0 *10^-⁹ M in water at 25°C, then __________

Which sketch best represents the qualitative molecular view of an aqueous solution of nitrous acid? (Water molecules are not shown explicitly.)

When pure water autoionizes, the following species are produced: __________

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

Quiz 17: Equilibrium in the Aqueous Phase

When [H+] = 1.0*10-7 M in water at 25°C, then __________

Ammonia (NH3) acts as a weak base in aqueous solution. What is the acid that reacts with this base when ammonia is dissolved in water?

Which of these is a strong acid that ionizes to make a weak acid?

In the following reaction in aqueous solution, the acid reactant is __________, and its conjugate base product is __________. CH3NH2 + HSO4- CH3NH3+ + SO42-

In the Brønsted-Lowry definition of acids and bases, a base __________

In the following reaction in aqueous solution, the acid reactant is __________ and its conjugate base product is __________. CH3COOH + NH3 CH3COO- + NH4+

The degree of ionization of a weak acid __________ (I) varies with the concentration of the acid. (II) depends on which weak acid it is. (III) is 100%. (IV) is greater than 50% but less than 100%.

A solution with pH of 9.50 has a pOH of __________

The base ionization constant Kb describes which of the following reactions for a weak base, B, in aqueous solution?

The degree of ionization of a strong acid is __________

Which one, A-D, is not related to the water autoionization constant, Kw? If all are related, respond E.

The acid ionization equilibrium constant, Ka, describes the reaction (where HA is a generic weak acid) :

Which sketch best represents the qualitative molecular view of an aqueous solution of nitric acid? (Water molecules are not shown explicitly.)

In the Brønsted-Lowry definition of acids and bases, an acid __________

Which statement about nitrous acid and nitric acid is correct?

A solution with a pOH of 6.92 has an [OH-] concentration of __________

When [H+] = 4.0 *10-9 M in water at 25°C, then __________

Which sketch best represents the qualitative molecular view of an aqueous solution of nitrous acid? (Water molecules are not shown explicitly.)

When pure water autoionizes, the following species are produced: __________

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

When [H⁺] = 1.0*10^-⁷ M in water at 25°C, then __________

Ammonia (NH₃) acts as a weak base in aqueous solution. What is the acid that reacts with this base when ammonia is dissolved in water?

In the following reaction in aqueous solution, the acid reactant is , and its conjugate base product is . CH₃NH₂ + HSO₄^- CH₃NH₃⁺ + SO₄²^-

In the following reaction in aqueous solution, the acid reactant is and its conjugate base product is . CH₃COOH + NH₃ CH₃COO^- + NH₄⁺

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

Which one, A-D, is not related to the water autoionization constant, K_w? If all are related, respond E.

The acid ionization equilibrium constant, K_a, describes the reaction (where HA is a generic weak acid) :

A solution with a pOH of 6.92 has an [OH^-] concentration of __________

When [H⁺] = 4.0 *10^-⁹ M in water at 25°C, then __________