Acids & Bases I

Multiple Choice

According to the Brønsted–Lowry theory, what is the main difference between an acid and a base?

• An acid donates H+ ions, while a base accepts H+ ions.

• An acid accepts H+ ions, while a base donates H+ ions.

• An acid donates OH- ions, while a base accepts OH- ions.

• An acid accepts OH- ions, while a base donates OH- ions.

Multiple Choice

Which species acts as the Brønsted–Lowry base in the reaction between ammonia and water?

• NH3

• H2O

• NH4+

• OH-

Open Ended

In each of the following equations, identify the Brønsted–Lowry acid and base in the reactants: A. HNO3(aq) + H2O(l) → H3O+(aq) + NO3−(aq) B. HF(aq) + H2O(l) ⇌ H3O+(aq) + F−(aq)

Multiple Choice

Which of the following statements about conjugate acid–base pairs is correct?

• Each pair is related by the loss and gain of H+.

• Only one pair occurs in the forward direction.

• There is only one conjugate acid–base pair in a reaction.

• Conjugate acid–base pairs are unrelated to H+ transfer.

Multiple Select

Select all correct statements about the conjugate acid–base pairs in the reaction between HF and H2O.

• HF donates H+ to form F−.

• H2O accepts H+ to form H3O+.

• F− is the conjugate acid of HF.

• H3O+ is the conjugate base of H2O.

Fill in the Blanks

In the reaction of NH3 and H2O, one conjugate acid–base pair is NH3/

and the other is H2O/H3O+.

Multiple Select

Which of the following sets contains an acid–base conjugate pair?

• HNO2, NO2-

• H2CO3, CO3^2-

• HCl, ClO4-

• HS-, H2S

Multiple Choice

Which statement best describes an amphoteric substance?

• It can act only as an acid.

• It can act only as a base.

• It can act as both an acid and a base.

• It cannot react with acids or bases.

Fill in the Blanks

Hydrofluoric acid, HF, is the only halogen that forms a

acid.

Multiple Choice

Which of the following statements best describes the difference between strong acids and weak acids in water?

• Strong acids dissociate completely into ions, while weak acids only partially dissociate.

• Strong acids and weak acids both dissociate completely into ions.

• Weak acids produce large concentrations of ions, while strong acids produce small concentrations.

• Strong acids remain mostly undissociated, while weak acids dissociate completely.

Multiple Choice

Which of the following pairs correctly matches the acid with its conjugate base as shown in the table of relative strengths?

• Hydrochloric acid (HCl) – Chloride ion (Cl-)

• Sulfuric acid (H2SO4) – Nitrate ion (NO3-)

• Acetic acid (CH3COOH) – Hydroxide ion (OH-)

• Hydrofluoric acid (HF) – Bromide ion (Br-)

Multiple Choice

Which of the following acids are classified as strong acids according to Table 11.3?

• Hydrochloric acid (HCl)

• Acetic acid (CH3COOH)

• Hydrofluoric acid (HF)

• Carbonic acid (H2CO3)

Fill in the Blanks

In the dissociation of carbonic acid, the first dissociation produces

and HCO3-.

Multiple Choice

Which of the following statements best explains why sulfuric acid is considered a diprotic acid?

• It contains two sulfur atoms.

• It can donate two protons, one at a time.

• It is a weak acid.

• It produces only one type of ion in solution.

Fill in the Blanks

Fill in the blank: Ammonia is a

base.

Multiple Select

Which of the following are strong bases?

• LiOH

• NH3

• NaOH

• KOH

Multiple Choice

Which of the following statements is true about the direction of acid-base reactions?

• The stronger acid always forms a stronger base.

• The weaker acid always forms a weaker base.

• The reaction favors the formation of the weaker acid and weaker base.

• The reaction favors the formation of the stronger acid and stronger base.

Multiple Choice

According to the Brønsted–Lowry theory, which of the following best describes an acid?

• A substance that donates H⁺ ions

• A substance that accepts H⁺ ions

• A substance that forms water

• A substance that forms chloride ions