Question 1

What are the two acids in the following reaction? NH₄⁺(aq) + HPO₄²⁻ ⇋ NH₃ + H₂PO₄⁻

Accepted Answer

The acids present in this reaction are H₂PO₄⁻ and H₂PO₄⁻, which combine to form H₂PO₄⁻. The other options do not contain two different acids that can combine to form a new compound.

Question 2

Which of the following represents the correct set of major species that are present in the solution when acetic acid (CH₃COOH) reacts with ammonia (NH₃)?

Accepted Answer

When acetic acid (CH₃COOH) reacts with ammonia (NH₃), the acid-base reaction takes place resulting in the formation of ammonium ion (NH₄⁺) and acetate ion (CH₃COO⁻). Therefore, the correct set of major species present in the solution is acetate ion and ammonium ion which is option D.

Question 3

The K_a of boric acid is 7.3 × 10⁻¹⁰. What is the pK_a of boric acid?

Accepted Answer

The answer of The K_a of boric acid is 7.3...

Question 4

Which of the following is true of the position of the equilibrium established when acetate ions react with hydrogen sulfide as represented below? CH₃COO⁻ + H₂S ⇋ CH₃COOH + HS⁻

Accepted Answer

The position of equilibrium will favor the side with the weaker acid and weaker base. In this reaction, the acetate ion is a weaker acid than hydrogen sulfide and the acetate ion is also a weaker base than hydrogen sulfide. Therefore, the equilibrium will lie to the left, favoring the side with the weaker acid (acetate ion) and weaker base (acetate ion).

Question 5

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Accepted Answer

We use the pKa values of the acids to determine their strengths. The lower the pKa value, the stronger the acid.

Question 6

Which factor(s) do we use to determine the stronger acid when comparing the strengths of two weak acids?

Accepted Answer

The strength of a weak acid is determined by its acid dissociation constant (Ka) and its pKa value. Both of these factors indicate how well an acid donates its proton in solution. The higher the Ka and the lower the pKa, the stronger the acid.

Question 7

The K_a of lactic acid is 8.4 × 10⁻⁴. What is the pK_a of lactic acid?

Accepted Answer

The pKa is calculated using the formula pKa = -log(Ka), where Ka is the acid dissociation constant. Given Ka = 8.4 × 10^-4, pKa = -log(8.4 × 10^-4) = 3.08.

Question 8

Which of the following is true of the position of equilibrium in an acid-base reaction?

Accepted Answer

The position of equilibrium in an acid-base reaction favors the formation of the weaker acid and weaker base. This is because stronger acids and bases react more completely to form weaker conjugates, thus shifting the equilibrium towards the side with the weaker species.

Question 9

Which of the following is true of the position of the equilibrium established when acetic acid is dissolved in water as represented below? CH₃COOH(aq) + H₂O ⇋ CH₃COO⁻(aq) + H₃O⁺(aq)

Accepted Answer

The equilibrium of acetic acid dissolving in water lies to the left because acetic acid is a weak acid and water is a weak base, making the reactants (left side) consist of the weaker acid and base compared to the products on the right.

Question 10

Consider the following hypothetical acid-base reaction. A(aq) + B(aq) ⇋ C(aq) + D(aq)
(weaker acid + weaker base ⇋ stronger acid + stronger base)
Which of the following statements is true of this reaction?

Accepted Answer

The position of the equilibrium favors the reverse reaction because reactions tend to favor the formation of the weaker acid and base from the stronger ones.

Question 11

Which of the following is true of the position of the equilibrium established when HCl is dissolved in water?

Accepted Answer

When HCl is dissolved in water, it almost completely dissociates into H+ and Cl- ions, indicating that the equilibrium lies to the right. This is because the products of the reaction (H3O+ and Cl-) are weaker as an acid and a base respectively than the reactants (HCl and H2O), thus the equilibrium favors the formation of these weaker species.

Question 12

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Accepted Answer

The strength of a weak acid is determined by its acid dissociation constant (Ka) value. The higher the Ka value, the stronger the acid. Therefore, to compare the strengths of two weak acids, we would look at their respective Ka values and choose the one with the higher value as the stronger acid.

Question 13

Which of the following is true when comparing two acids?

Accepted Answer

The strength of an acid is directly related to its acid dissociation constant (K_a); a larger K_a indicates a stronger acid. The pK_a is the negative logarithm of K_a, so a smaller pK_a also indicates a stronger acid. Therefore, both A and B are true, making C the correct choice.

Question 14

Ammonia, NH₃, is a stronger base than the acetate ion, CH₃COO⁻. Which of the following represents the correct set of species that are present in the solution in the largest amounts when acetic acid (CH₃COOH) reacts with ammonia (NH₃)?

Accepted Answer

When acetic acid reacts with ammonia, the ammonia acts as a base and accepts a proton from the acetic acid, forming the acetate ion and the ammonium ion. These are the products of the reaction and will be present in the largest amounts.

Question 15

Which of the following is true when comparing two acids?

Accepted Answer

The stronger acid has a larger K_a and a smaller pK_a.

Question 16

Which of the following is the stronger base in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?

Accepted Answer

In an acid-base equilibrium, the stronger base is the one that will more readily accept a proton. In this case, H₂O is the stronger base because it has a more stable conjugate acid than the other options. This is because the conjugate acid of H₂O (H2₂O) has a more stable negative charge on the oxygen atom compared to the other conjugate acids. Therefore, H₂O is more likely to accept a proton and form the more stable conjugate acid.

Question 17

Hydrocyanic acid (HCN) is a weaker acid than ammonium ion (NH₄⁺). Which of the following represents the correct set of major species that are present in the solution when hydrocyanic acid (HCN) reacts with ammonia (NH₃)?

Accepted Answer

The answer of Hydrocyanic acid (HCN) is a weaker acid...

Question 18

Cyanide ion, CN⁻, is a stronger base than ammonia, NH₃. Which of the following represents the correct set of species that are present in the solution in the largest amounts when ammonia (NH₃) reacts with hydrocyanic acid (HCN)?

Accepted Answer

The answer of Cyanide ion, CN⁻, is a stronger base...

Question 19

Which of the following is true when comparing two acids?

Accepted Answer

The strength of an acid is determined by its acid dissociation constant (K_a). A larger K_a indicates a stronger acid, while a larger pK_a (which is the negative logarithm of K_a) indicates a weaker acid.

Question 20

Which of the following is the stronger acid in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?

Accepted Answer

The answer of Which of the following is the stronger...

Quiz 8: Acids and Bases

What are the two acids in the following reaction? NH₄⁺(aq) + HPO₄²⁻ ⇋ NH₃ + H₂PO₄⁻

Which of the following represents the correct set of major species that are present in the solution when acetic acid (CH₃COOH) reacts with ammonia (NH₃) ?

The K_a of boric acid is 7.3 × 10⁻¹⁰. What is the pK_a of boric acid?

Which of the following is true of the position of the equilibrium established when acetate ions react with hydrogen sulfide as represented below? CH₃COO⁻ + H₂S ⇋ CH₃COOH + HS⁻

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Which factor(s) do we use to determine the stronger acid when comparing the strengths of two weak acids?

The K_a of lactic acid is 8.4 × 10⁻⁴. What is the pK_a of lactic acid?

Which of the following is true of the position of equilibrium in an acid-base reaction?

Which of the following is true of the position of the equilibrium established when acetic acid is dissolved in water as represented below? CH₃COOH(aq) + H₂O ⇋ CH₃COO⁻(aq) + H₃O⁺(aq)

Consider the following hypothetical acid-base reaction. A(aq) + B(aq) ⇋ C(aq) + D(aq) (weaker acid + weaker base ⇋ stronger acid + stronger base) Which of the following statements is true of this reaction?

Which of the following is true of the position of the equilibrium established when HCl is dissolved in water?

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Which of the following is true when comparing two acids?

Ammonia, NH₃, is a stronger base than the acetate ion, CH₃COO⁻. Which of the following represents the correct set of species that are present in the solution in the largest amounts when acetic acid (CH₃COOH) reacts with ammonia (NH₃) ?

Which of the following is true when comparing two acids?

Which of the following is the stronger base in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?

Hydrocyanic acid (HCN) is a weaker acid than ammonium ion (NH₄⁺) . Which of the following represents the correct set of major species that are present in the solution when hydrocyanic acid (HCN) reacts with ammonia (NH₃) ?

Cyanide ion, CN⁻, is a stronger base than ammonia, NH₃. Which of the following represents the correct set of species that are present in the solution in the largest amounts when ammonia (NH₃) reacts with hydrocyanic acid (HCN) ?

Which of the following is true when comparing two acids?

Which of the following is the stronger acid in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?

Quiz 8: Acids and Bases

What are the two acids in the following reaction? NH4+(aq) + HPO42− ⇋ NH3 + H2PO4−

Which of the following represents the correct set of major species that are present in the solution when acetic acid (CH3COOH) reacts with ammonia (NH3) ?

The Ka of boric acid is 7.3 × 10−10. What is the pKa of boric acid?

Which of the following is true of the position of the equilibrium established when acetate ions react with hydrogen sulfide as represented below? CH3COO− + H2S ⇋ CH3COOH + HS−

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Which factor(s) do we use to determine the stronger acid when comparing the strengths of two weak acids?

The Ka of lactic acid is 8.4 × 10−4. What is the pKa of lactic acid?

Which of the following is true of the position of equilibrium in an acid-base reaction?

Which of the following is true of the position of the equilibrium established when acetic acid is dissolved in water as represented below? CH3COOH(aq) + H2O ⇋ CH3COO−(aq) + H3O+(aq)

Consider the following hypothetical acid-base reaction. A(aq) + B(aq) ⇋ C(aq) + D(aq) (weaker acid + weaker base ⇋ stronger acid + stronger base) Which of the following statements is true of this reaction?

Which of the following is true of the position of the equilibrium established when HCl is dissolved in water?

Which factor do we use to determine the stronger acid when comparing the strengths of two weak acids?

Which of the following is true when comparing two acids?

Ammonia, NH3, is a stronger base than the acetate ion, CH3COO−. Which of the following represents the correct set of species that are present in the solution in the largest amounts when acetic acid (CH3COOH) reacts with ammonia (NH3) ?

Which of the following is true when comparing two acids?

Which of the following is the stronger base in the acid-base equilibrium H3O+ + I− ⇋ H2O + HI?

Hydrocyanic acid (HCN) is a weaker acid than ammonium ion (NH4+) . Which of the following represents the correct set of major species that are present in the solution when hydrocyanic acid (HCN) reacts with ammonia (NH3) ?

Cyanide ion, CN−, is a stronger base than ammonia, NH3. Which of the following represents the correct set of species that are present in the solution in the largest amounts when ammonia (NH3) reacts with hydrocyanic acid (HCN) ?

Which of the following is true when comparing two acids?

Which of the following is the stronger acid in the acid-base equilibrium H3O+ + I− ⇋ H2O + HI?

What are the two acids in the following reaction? NH₄⁺(aq) + HPO₄²⁻ ⇋ NH₃ + H₂PO₄⁻

Which of the following represents the correct set of major species that are present in the solution when acetic acid (CH₃COOH) reacts with ammonia (NH₃) ?

The K_a of boric acid is 7.3 × 10⁻¹⁰. What is the pK_a of boric acid?

Which of the following is true of the position of the equilibrium established when acetate ions react with hydrogen sulfide as represented below? CH₃COO⁻ + H₂S ⇋ CH₃COOH + HS⁻

The K_a of lactic acid is 8.4 × 10⁻⁴. What is the pK_a of lactic acid?

Which of the following is true of the position of the equilibrium established when acetic acid is dissolved in water as represented below? CH₃COOH(aq) + H₂O ⇋ CH₃COO⁻(aq) + H₃O⁺(aq)

Ammonia, NH₃, is a stronger base than the acetate ion, CH₃COO⁻. Which of the following represents the correct set of species that are present in the solution in the largest amounts when acetic acid (CH₃COOH) reacts with ammonia (NH₃) ?

Which of the following is the stronger base in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?

Hydrocyanic acid (HCN) is a weaker acid than ammonium ion (NH₄⁺) . Which of the following represents the correct set of major species that are present in the solution when hydrocyanic acid (HCN) reacts with ammonia (NH₃) ?

Cyanide ion, CN⁻, is a stronger base than ammonia, NH₃. Which of the following represents the correct set of species that are present in the solution in the largest amounts when ammonia (NH₃) reacts with hydrocyanic acid (HCN) ?

Which of the following is the stronger acid in the acid-base equilibrium H₃O⁺ + I⁻ ⇋ H₂O + HI?