Question 1

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 reacts with water (H₂O) itself, which acts as the acid in this reaction. This is because water can donate a proton (H⁺) to ammonia, forming the ammonium ion (NH₄⁺) and hydroxide ion (OH⁻).

Question 2

Which of the following statements regarding the leveling effect is NOT correct?

Accepted Answer

The leveling effect refers to the phenomenon where strong acids or bases in water all appear to have the same strength due to the solvent's (water's) limiting effect. However, this does not imply that all strong acids and bases are equally strong in solvents other than water, where their intrinsic strengths can be differentiated.

Question 3

Suppose an aqueous solution initially contains one mole of hydrochloric acid and one mole of ammonia.Which of the following statements best describes the solution once it comes to equilibrium?

Accepted Answer

The solution is slightly acidic because the reaction between NH3 and HCl forms NH4+, which can slightly dissociate back to NH3 and H+, leading to a slightly acidic solution.

Question 4

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

Accepted Answer

The answer of Which of the following is a conjugate...

Question 5

In the following reaction in aqueous solution, the acid reactant is _______ and its conjugate base product is _______. CH₃ COOH(aq) +NH₃ (aq) ⇄ CH₃COO^-(aq) +NH₄ ⁺ (aq)

Accepted Answer

The acid reactant is CH3COOH, and its conjugate base product is CH3COO^-.

Question 6

When pure water autoionizes, which species are produced?

Accepted Answer

When pure water autoionizes, it produces hydroxide ions (OH-) and hydronium ions (H3O+), which are represented in choice B.

Question 7

Which of the following is correct?

Accepted Answer

The answer of Which of the following is correct?
...

Question 8

Which of the following is NOT a conjugate acid-base pair?

Accepted Answer

The answer of Which of the following is NOT a...

Question 9

Which ending to the statement is NOT correct? The weak acid HY will be stronger than the weak acid HZ if

Accepted Answer

The strength of a weak acid is not directly related to the polarity of its bonds but rather to its ability to donate a proton. A less polar bond does not necessarily make HY a stronger acid than HZ; factors like resonance stabilization, electronegativity, and the number of oxygen atoms are more directly influential.

Question 10

Which of the following cannot be a Brønsted-Lowry base?

Accepted Answer

NH₄⁺ cannot be a Brønsted-Lowry base because it cannot accept a proton; it is already a protonated form of ammonia (NH₃), which can act as a base.

Question 11

In each of the following, the stronger acid is identified and an explanation is given.All except one are correct statements.Which one is NOT correct?

Accepted Answer

The incorrect statement is B because it incorrectly suggests that a negative charge directly stabilizes the loss of a proton in acids, which is a misinterpretation. The acidity in organic compounds is often influenced by the ability of the structure to stabilize the conjugate base through resonance or inductive effects, not merely by the presence of a negative charge.

Question 12

Which of the following is NOT correct?

Accepted Answer

HCl (hydrochloric acid) is a strong acid, stronger than HClO (hypochlorous acid). The strength of an acid in aqueous solution depends on its ability to donate a proton (H+), and HCl dissociates completely in water, making it a stronger acid compared to HClO, which is a weak acid and does not dissociate completely.

Question 13

Which of the following statements regarding acidity, basicity, pH, and pOH is NOT correct?

Accepted Answer

The correct relationship between pH and [H+] is inverse; as pH increases, the concentration of hydrogen ions ([H+]) decreases, not increases.

Question 14

Which expression defines the autoionization constant for water, K_w?

Accepted Answer

The autoionization constant for water, $K_w$, is defined by the concentration of hydrogen ions $[H^+]$ and hydroxide ions $[OH^-]$ in water, which is correctly represented in option A.

Question 15

Which of the following lists the conjugate acid of HAsO₄^2- first and its conjugate base second?

Accepted Answer

The conjugate acid of HAsO₄²⁻ is H₂AsO₄⁻, and the conjugate base is AsO₄³⁻.

Question 16

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

Accepted Answer

The answer of Which of the following is a conjugate...

Question 17

In the following reaction in aqueous solution, the acid reactant is _______ and the base reactant is _______. OH^-(aq) +C₆H₅ NH₃ ⁺(aq) ⇄ C₆ H₅ NH₂ (aq) F+H₂O(l)

Accepted Answer

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

Question 18

Which of the following is NOT related to the water autoionization constant, K_w?

Accepted Answer

All options (A, B, C, D) are related to the water autoionization constant, $K_w$. Option A represents the ion product of water ($[H^+][OH^-]$), B gives the value of $K_w$ at 25°C, C describes the autoionization reaction of water, and D indicates the neutral pH value resulting from water autoionization at 25°C.

Question 19

Which statement is NOT correct? Pure water at 25°C has

Accepted Answer

All statements, despite the formatting issues, aim to convey properties of pure water at 25°C: its ion product (Kw), pOH, concentration of H3O+ and OH- ions, and pH, which are all correctly associated with pure water at this temperature.

Question 20

Which of the following statements is NOT correct?

Accepted Answer

HIO (hypoiodous acid) is actually a weaker acid than HClO (hypochlorous acid), due to the lower electronegativity of iodine compared to chlorine, which makes HIO less able to stabilize the negative charge on the oxygen in its conjugate base.

Quiz 15: Acid-Base Equilibria Proton Transfer in Biological Systems

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 the following statements regarding the leveling effect is NOT correct?

Suppose an aqueous solution initially contains one mole of hydrochloric acid and one mole of ammonia.Which of the following statements best describes the solution once it comes to equilibrium?

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

In the following reaction in aqueous solution, the acid reactant is _ and its conjugate base product is _. CH₃ COOH(aq) +NH₃ (aq) ⇄ CH₃COO^-(aq) +NH₄ ⁺ (aq)

When pure water autoionizes, which species are produced?

Which of the following is correct?

Which of the following is NOT a conjugate acid-base pair?

Which ending to the statement is NOT correct? The weak acid HY will be stronger than the weak acid HZ if

Which of the following cannot be a Brønsted-Lowry base?

In each of the following, the stronger acid is identified and an explanation is given.All except one are correct statements.Which one is NOT correct?

Which of the following is NOT correct?

Which of the following statements regarding acidity, basicity, pH, and pOH is NOT correct?

Which expression defines the autoionization constant for water, K_w?

Which of the following lists the conjugate acid of HAsO₄^2- first and its conjugate base second?

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

In the following reaction in aqueous solution, the acid reactant is _ and the base reactant is _. OH^-(aq) +C₆H₅ NH₃ ⁺(aq) ⇄ C₆ H₅ NH₂ (aq) F+H₂O(l)

Which of the following is NOT related to the water autoionization constant, K_w?

Which statement is NOT correct? Pure water at 25°C has

Which of the following statements is NOT correct?

Quiz 15: Acid-Base Equilibria Proton Transfer in Biological Systems

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 the following statements regarding the leveling effect is NOT correct?

Suppose an aqueous solution initially contains one mole of hydrochloric acid and one mole of ammonia.Which of the following statements best describes the solution once it comes to equilibrium?

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

In the following reaction in aqueous solution, the acid reactant is _______ and its conjugate base product is _______. CH3 COOH(aq) +NH3 (aq) ⇄ CH3COO-(aq) +NH4 + (aq)

When pure water autoionizes, which species are produced?

Which of the following is correct?

Which of the following is NOT a conjugate acid-base pair?

Which ending to the statement is NOT correct? The weak acid HY will be stronger than the weak acid HZ if

Which of the following cannot be a Brønsted-Lowry base?

In each of the following, the stronger acid is identified and an explanation is given.All except one are correct statements.Which one is NOT correct?

Which of the following is NOT correct?

Which of the following statements regarding acidity, basicity, pH, and pOH is NOT correct?

Which expression defines the autoionization constant for water, Kw?

Which of the following lists the conjugate acid of HAsO42- first and its conjugate base second?

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

In the following reaction in aqueous solution, the acid reactant is _______ and the base reactant is _______. OH-(aq) +C6H5 NH3 +(aq) ⇄ C6 H5 NH2 (aq) F+H2O(l)

Which of the following is NOT related to the water autoionization constant, Kw?

Which statement is NOT correct? Pure water at 25°C has

Which of the following statements is NOT correct?

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 _. CH₃ COOH(aq) +NH₃ (aq) ⇄ CH₃COO^-(aq) +NH₄ ⁺ (aq)

Which expression defines the autoionization constant for water, K_w?

Which of the following lists the conjugate acid of HAsO₄^2- first and its conjugate base second?

In the following reaction in aqueous solution, the acid reactant is _ and the base reactant is _. OH^-(aq) +C₆H₅ NH₃ ⁺(aq) ⇄ C₆ H₅ NH₂ (aq) F+H₂O(l)

Which of the following is NOT related to the water autoionization constant, K_w?