SB 17.9-17.10
Which of the following acids are polyprotic?
H3PO4 H2SO3
Which of the following salt solutions will be basic, assuming that all have concentrations of 0.1 M?
NaCN KCH3COO
The pH of a salt solution containing a small, highly charged metal cation is influenced by the hydrolysis reaction of the metal ion. Which of the following statements correctly explain the hydrolysis reaction of these metal cations?
-Small, highly charged metal cations accept electron pairs from water molecules and form hydrated ions. -A hydrated metal ion produces an acidic solution because the metal ion withdraws electron density from the O-H bond, facilitating loss of H+.
Rank the following 0.1 M salt solutions in order of increasing pH (lowest pH at the top of the list).
1. NaHSO₄ 2. NH₄NO₃ 3. NaHCO₃ 4. Na₂CO₃
Match each acid correctly to the number of ionizable protons. H3PO4, H2CO3, CH3COOH
3, 2, 1
Which of the following statements correctly describe the acid-base properties of a 1.0-M solution of methylammonium fluoride (CH3NH3F)? Select all that apply. Ka of HF = 7.1 × 10-4 and Kb of CH3NH2 = 4.4 × 10-4
Both CH3NH3+ and F- will hydrolyze (react with water) in aqueous solution. The solution will be slightly acidic because Ka of CH3NH3+ > Kb of F-. Ka of CH3NH3+ = 2.3 × 10-11
Which of the following statements correctly describe the acid-base properties of a 0.10-M solution of ammonium cyanide (NH4CN)? Select all that apply. Ka of NH4+ = 5.6 x 10-10 and Kb of CN- = 1.8 x 10-5.
Both NH4+ and CN- will hydrolyze (react with water) in aqueous solution. CN- will behave as a base when it reacts with water. The solution will be basic.
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.
Cl− I− NO−3
In order to determine whether a solution of NH4C2H3O2 is acidic, basic, or neutral, what two values could be compared?
Ka of NH4+ Kb of CH3COO-
Which of the following statements is NOT a characteristic of polyprotic acids?
Polyprotic acids are generally strong acids in their first ionization.
Which of the following statements accurately describe the characteristics of polyprotic acids?
Polyprotic acids are generally weak acids. A polyprotic acid has more than one ionizable proton. In calculations involving polyprotic acids we generally only take into account H3O+ formed from the first ionization.
An aqueous NaCl solution was found to have a pH = 7.00.
The NaCl solution was neutral. Neither Na+ nor Cl- reacts with water.
Which of the following statements correctly describe salt hydrolysis?
The ions produced by dissociation of a salt in water react with H2O. Salt hydrolysis may cause the pH of the resulting solution to be above or below 7.00. Both the anion and the cation of a water-soluble salt may interact with water.
Calculate and compare the pH values for 0.10 M solutions of NH4Br (Ka 5.6 × 10-10) and Al(NO3)3 (Ka 1.3 × 10-5). Which of the following statements correctly describe the acidity of these solutions?
The pH of the Al(NO3)3 solution is 2.94. The NH4Br solution has a higher pH than the Al(NO3)3 solution.
Ka (of the salt's cation) > Kb (of the salt's anion)
The salt solution is acidic.
Ka (of the salt's cation) < Kb (of the salt's anion)
The salt solution is basic.
Ka (of the salt's cation) ≈ Kb (of the salt's anion)
The salt solution is neutral.
Select all the options that correctly account for the behavior of NH4Cl in aqueous solution.
The solution will have a pH < 7.00. NH4+ + H2O ⇌ NH3 + H3O+
What is the name given to SO2 in the troposphere that is oxidized to H2SO4 in the form of aerosol which ends up in wet precipitation?
acid rain
A salt in which the cation is the conjugate acid of a weak base will be ______. (Assume that the anion does not hydrolyze.)
acidic
NH4I
acidic
A salt consisting of a small, highly charged metal cation and the anion of a strong acid yields a(n) _____ solution.
acidic Reason: The cation acts as a weak acid, and the anion does not react.
A salt consisting of the _____ of a strong acid and the _____ of a strong base yields a neutral solution.
anion; cation
A salt in which the anion is the conjugate _____ of a weak _____ will produce a basic solution. (Assume that the cation does not hydrolyze.)
base, acid
KCN
basic
When an ionic compound dissociates in water, the separated ions may react with H2O to produce H3O+ or OH- ions. This process, known as salt _____, may affect the _____ of the salt solution.
hydrolysis; pH
KBr
neutral
Hydrated _____ metal cations act as weak acids because these metal ions are so successful at withdrawing electron density from the O-H bond of water, thus facilitating the loss of H+ to the solvent water to form H3O+
small, highly charged
A salt consisting of the conjugate base of a ____________ and conjugate acid of a ____________ will be neutral since neither will react with water.
strong acid; strong base
The salt consisting of the conjugate base of a _____ and the conjugate acid of a _____ will be acidic since the conjugate _____ of a _____ is acidic.
strong acid; weak base; acid; weak base
A salt consisting of the conjugate base of a _____ and the conjugate acid of a _____ will be basic since the conjugate _____ of a _____ is basic.
weak acid; strong base; base; weak acid
A salt consisting of the conjugate base of a _____ and conjugate acid of a _____ can be either acidic or basic depending on the relative Ka and Kb of the respective ions.
weak acid; weak base
