Chapter 18

Which of the following statements correctly describes the behavior of strong acids, HA, in aqueous solution?

Strong acid molecules are not present in aqueous solutions. A strong acid dissociates completely into ions in water. [H3O+] = [A-] ≈ [HA]init

Which of the following species usually act as weak bases? Select all that apply. Multiple select question.

PO43- CH3NH2 CH3COO-

Which of the following factors will affect the relative strength of oxoacids? Select all that apply. Multiple select question.

The number of O atoms attached to the central nonmetal atom The electronegativity of the central nonmetal atom

Select all the statements that correctly describe the aqueous solution of a metal cation.

A metal cation can withdraw electron density from the O-H bonds of H2O molecules, releasing H+ ions. A solution containing small, highly charged metal cations will be acidic.

Metal cations act like ______ when dissolved in water. The hydrated cation is the ____

Lewis acids; adduct

Which of the following statements describe the behavior of strong and weak acids (general formula HA) in aqueous solution? Select all that apply.

A weak acid is a weak electrolyte. The solution of a strong acid will have extremely few to no undissociated HA molecules.

Select all the compounds in the following list that are strong bases.

CaO NaOH

Which of the following anions will produce a neutral solution in water? Select all that apply, and assume that any associated cations do not affect the pH.

I- NO3- Cl-

Which of the following options correctly describe the structural characteristics of strong and weak bases? Select all that apply.

Amines such as CH3CH2NH2 are weak bases. Compounds that contain electron-rich N are weak bases. Soluble hydroxides are strong bases.

A salt consisting of the _____ of a strong acid and the _____ of a strong base yields a neutral solution. Multiple choice question.

Anion;Cations

Which of the following species are Lewis acids? Select all that apply.

BF3 Cu2+ SO3

Which of the following compounds can be classified as bases according to the Arrhenius definition? Select all that apply.

Ba(OH)2 NaOH

Which of the following options correctly describe the constant Ka? Select all that apply.

Ka is the acid-dissociation constant. [H2O] is not included in the Ka expression for a particular acid.

In order to determine whether a solution of NH4C2H3O2 is acidic, basic, or neutral, what two values could be compared?

Kb of CH3COO- Ka of NH4+

Which of the following common household substances are bases? Select all that apply. Multiple select question.

Lye Baking Soda NH3

Which of the following types of substances are classified as acids only under the Lewis definition? Select all that apply. Multiple select question.

Molecules with electron deficient central atoms Molecules that contain a polar multiple bond

The direction of an acid-base equilibrium depends on the relative strengths of the acids and bases involved. Since strong acids and strong bases readily accept and donate protons, the equilibrium will always favor the reaction of the _____ acid and base and the formation of the _____ acid and base. Multiple choice question.

Stronger;weaker

Select the correct statements describing a solution containing a salt composed of the cation of a strong base and the anion of a polyprotic acid. Select all that apply.

The cation has no impact on the pH of the solution. The anion will hydrolyze to produce either H3O+ or OH- ions depending on the relative values of Ka and Kb of the anion.

Select the correct statements describing a solution containing a salt composed of the cation of a strong base and the anion of a polyprotic acid. Select all that apply. Multiple select question.

The cation has no impact on the pH of the solution. The anion will hydrolyze to produce either H3O+ or OH- ions depending on the relative values of Ka and Kb of the anion.

How does a conjugate acid differ from its conjugate base? Select all that apply.

The conjugate acid has one more H than its conjugate base. A conjugate base may be positively charged, neutral, or negatively charged. The conjugate acid of a neutral base will have a charge of +1.

Select all the factors that affect the ease with which a proton is released from a nonmetal hydride (represented by the general formula E-H.)

The electronegativity of the central atom (E) The strength of the E-H bond

Which of the following statements correctly describe a 1.0 M solution of KCN? Select all that apply.

The solution is basic. The solution contains a significant concentration of the weak base CN-.

A Bronsted-Lowry acid is a proton _____ and must therefore contain at least one ionizable _____ atom in its formula

donor:hydrogen

Calculate the pH and [H3O+] of a 0.080 M solution of NaOH.

pH = 12.90 [H3O+] = 1.3 x 10-13 M

Acid dissociation is represented by the general equation HA + H2O (l) ⇌ H3O+ (aq) + A- (aq). For a strong acid the equilibrium lies far to the _____ and [H3O+] is much _____ than [HA]. For a weak acid, on the other hand, the equilibrium lies far to the _____ and [H3O+] is much _____ than [HA].

right; higher; left; lower