Question 1

Carboxylic acids have the formula A) R-CH₃ B) R-CHO C) R-COOH D) R-NH₂ E) R-OH

Accepted Answer

Carboxylic acids have the functional group -COOH, which is represented by choice C in the options given.

Question 2

In terms of acid strength, which acid does not belong in a category with the others? A) HNO₂ B) HClO₄ C) HCOOH D) HF E) H₂SO₃

Accepted Answer

B

Question 3

Which reaction illustrates water acting as a base? A) Cu(H₂O)₄²⁺ + 4 NH₃ Cu(NH₃)₄²⁺ + 4 H₂O B) H₂CO₃ H₂O + CO₂ C) NH₃ + H₂O NH₄⁺ + OH^- D) H₂PO₄^- + H₂O OH^- + H₃PO₄ E) HSO₄^- + H₂O H₃O⁺ + SO₄^2-

Accepted Answer

E

Question 4

A Bronsted-Lowry base must have a(n) ____.
A) atom that does not obey the octet rule
B) atom with an unshared pair of electrons
C) nitrogen atom
D) amphiprotic atom
E) oxygen atom

Accepted Answer

A Bronsted-Lowry base is a molecule or ion that is capable of accepting a hydrogen ion (proton). For this to happen, the base must have a pair of electrons to form a bond with the proton. The only choice that describes a molecule with an unshared pair of electrons is B, so it is the best choice. None of the other choices are necessary for a molecule to be a Bronsted-Lowry base.

Question 5

A Bronsted-Lowry acid is always
A) a highly dissociated acid
B) a weak acid
C) both an acceptor and donor of hydrogen ions
D) a donor of one or more hydrogen ions
E) a molecule or ion in which hydrogen is attached to an oxygen atom

Accepted Answer

A Bronsted-Lowry acid is defined as a substance that donates one or more hydrogen ions (protons) to another substance. It does not have to be highly dissociated or weak, nor does it have to be attached to an oxygen atom. It is also not necessarily both an acceptor and donor of hydrogen ions - that would be a Lewis acid.

Question 6

Which cannot act as a Bronsted-Lowry acid? A) HPO₄^2- B) H₃O⁺ C) CH₃COO^- D) CH₃NH₃⁺ E) HCOOH

Accepted Answer

A Bronsted-Lowry acid is a species that can donate a proton (H⁺). CH₃COO^- is the acetate ion, which is the conjugate base of acetic acid and cannot donate a proton.

Question 7

The conjugate base of NH₃ is ____. A) H₂O B) OH^- C) D) NH₄OH E)

Accepted Answer

The answer of The conjugate base of NH₃ is ____. A)...

Question 8

Bronsted-Lowry acids ____ and Bronsted-Lowry bases ____. A) generate H₃O⁺ ions in aqueous solution; generate OH^- ions in aqueous solutions B) accept protons; generate OH^- ions in aqueous solutions C) generate OH^- ions in aqueous solution; generate H₃O⁺ ions in aqueous solutions D) generate H₃O⁺ ions in aqueous solution; donate protons in aqueous solutions E) donate protons; accept protons in aqueous solutions

Accepted Answer

Bronsted-Lowry acids are defined as proton (H+) donors, while Bronsted-Lowry bases are defined as proton (H+) acceptors. This definition does not depend on the generation of specific ions in solution.

Question 9

Which pair of substances represents a conjugate acid-base pair? A) CH₃COO^- and H₂O B) H₃O⁺ and OH^- C) CH₃COOH and CH₃COO^- D) CH₃COOH and H₃O⁺ E) CH₃COOH and OH^-

Accepted Answer

A conjugate acid-base pair consists of two species that differ by the presence or absence of a proton (H+). In option C, CH3COOH (acetic acid) can donate a proton to become CH3COO- (acetate ion), making them a conjugate acid-base pair.

Question 10

Because water can act as a Bronsted-Lowry acid or base, it is said to be ____.
A) amphiphilic
B) amphihydrous
C) amphiphobic
D) amphiprotic
E) amphoteric

Accepted Answer

Water can donate a proton (act as an acid) by losing H+ ion and also accept a proton (act as a base) by gaining H+ ion. Therefore, it is called amphiprotic. Among the given options, D is the only term that reflects this property of water. The other options do not relate to the acidic or basic behavior of water.

Question 11

Amines have the general formula A) R-CHO B) CH₃-(CH₂)_n-CH₃ C) R-COOH D) R-NH₂ E) R-OH

Accepted Answer

Amines have the general formula R-NH2 or R-NH-R' (secondary or tertiary amine). Option D has the correct functional group -NH2 for a primary amine (R-NH2). Options A, C, and E have different functional groups that are not amines. Option B is a complex chemical formula that does not represent any known functional group.

Question 12

In this reaction A) NH₃ acts as a base and OH^- as an acid. B) H₂O acts as an acid and NH₃ as a base. C) H₂O acts as a base and NH₄⁺ as an acid. D) H₂O acts as an acid and NH₄⁺ as a base. E) NH₃ acts as an acid and OH^- as a base.

Accepted Answer

According to the Brønsted-Lowry theory, an acid is a substance that donates a proton (H+) and a base is a substance that accepts a proton. In this reaction, H₂O is donating a proton (acting as an acid) to NH₃ which is accepting the proton (acting as a base). Therefore, option B is the correct answer.None of the other options follow this pattern of proton donation and acceptance.

Question 13

In terms of base strength, which base does not belong in a category with the others? A) Ba(OH)₂ B) NaOH C) Sr(OH)₂ D) LiOH E) NH₄OH

Accepted Answer

All other bases listed are hydroxides of metals commonly used in chemistry, while NH₄OH is a synthetic compound used in biological applications.

Question 14

Which pair of substances does not represent a conjugate acid-base pair? A) CH₃COOH and CH₃COO^- B) CH₃NH₃⁺ and CH₃NH₂ C) H₂SO₃ and HSO₄^- D) HPO₄^2- and PO₄^3- E) HCOOH and HCOO^-

Accepted Answer

H₂SO₃ and HSO₄^- are not a conjugate acid-base pair because they do not differ by a single proton.

Question 15

The reaction between acetic acid (CH₃COOH) and water is written as A) CH₃COOH + H₂O CH₂COOH^- + H₃O⁺ B) CH₃COOH + H₂O CH₃COO^- + OH^- C) CH₃COOH + H₂O CH₃COOH₂⁺ + OH^- D) CH₃COOH + H₂O CH₃COO^- + H₃O⁺ E) CH₃COOH + H₂O CH₃CO^- + OH^- + H₂O

Accepted Answer

The answer of The reaction between acetic acid (CH₃COOH) and...

Question 16

The product of the reaction between methylamine, CH₃NH₂, and hydrochloric acid are A) CH₄NH₂⁺ and Cl^- B) CH₃NH^- and H₂Cl⁺ C) CH₃NH₃⁺ and Cl^- D) CH₃NH₃^- and Cl⁺ E) CH₃NH₄²⁺ and 2Cl^-

Accepted Answer

When methylamine, CH₃NH₂, reacts with hydrochloric acid, HCl, the amine group (NH2) reacts with the proton (H+) from HCl to form the ammonium ion (NH3+), and the chloride ion (Cl-) is produced. This results in the formation of CH₃NH₃ and Cl^-. Therefore, the best choice is C.

Question 17

Which substance can act as a Bronsted-Lowry base, but not as a Bronsted-Lowry acid? A) HPO₄^2- B) H₂O C) NH₄⁺ D) PO₄^3- E) HSO₄^-

Accepted Answer

PO₄^3- can accept a proton to form HPO₄^2-, acting as a Bronsted-Lowry base, but it cannot donate a proton, so it cannot act as a Bronsted-Lowry acid.

Question 18

Which substance cannot act as a Bronsted-Lowry base? A) OH^- B) CH₃NH₂ C) NH₄⁺ D) NH₃ E) HSO₄^-

Accepted Answer

NH₄⁺ cannot act as a Bronsted-Lowry base because it cannot accept a proton; instead, it can donate a proton, acting as an acid.

Question 19

Methylamine, CH₃NH₂, acts as a weak base in water. The products of the reaction are ____ and ____. A) OH^- and CH₃NH₃⁺ B) H₃O⁺ and CH₃NH₃⁺ C) H₃O⁺ and OH^- D) OH^- and CH₃NH^- E) H₃O⁺ and CH₃NH^-

Accepted Answer

When methylamine (CH₃NH₂) acts as a base in water, it accepts a proton (H⁺) from water, forming methylammonium ion (CH₃NH₃⁺) and hydroxide ion (OH⁻).

Question 20

Which factor does not contribute to the acidity of the hydrogen atom in the carboxylic acid functional group?
A) the attraction of the O atoms in the carboxylic acid group for the electrons in the O-H bond
B) resonance stabilization of the resulting anion
C) the electronegativity of the C atom
D) the lack of polarity in the C-H bonds in the rest of the molecule
E) the electronegativity of the O that is bonded to the H

Accepted Answer

The answer of Which factor does not contribute to the...

Quiz 15: Acids and Bases

Carboxylic acids have the formula

In terms of acid strength, which acid does not belong in a category with the others?

Which reaction illustrates water acting as a base?

A Bronsted-Lowry base must have a(n) ____.

A Bronsted-Lowry acid is always

Which cannot act as a Bronsted-Lowry acid?

The conjugate base of NH₃ is ____.

Bronsted-Lowry acids and Bronsted-Lowry bases .

Which pair of substances represents a conjugate acid-base pair?

Because water can act as a Bronsted-Lowry acid or base, it is said to be ____.

Amines have the general formula

In this reaction

In terms of base strength, which base does not belong in a category with the others?

Which pair of substances does not represent a conjugate acid-base pair?

The reaction between acetic acid (CH₃COOH) and water is written as

The product of the reaction between methylamine, CH₃NH₂, and hydrochloric acid are

Which substance can act as a Bronsted-Lowry base, but not as a Bronsted-Lowry acid?

Which substance cannot act as a Bronsted-Lowry base?

Methylamine, CH₃NH₂, acts as a weak base in water. The products of the reaction are and .

Which factor does not contribute to the acidity of the hydrogen atom in the carboxylic acid functional group?