CH 16
CH 17
Solubility
Past Exams
Past Exams
100
A conjugate acid of H2O is
A- H3O+
B- OH-
C- H+
D- H2O
E- D2O
H3O+
100
Which solution below would have the lowest concentration of hydroxide ions?
A- pH=7.93
B- pH=7.00
C- pH=12.6
D- pH=3.22
E- pH=9.84
pH=3.22
100
Ferrous hydroxide is a slightly soluble base. Which of the following would dissolve Fe(OH)2 the least effectively?
A- 0.1 M HCl
B- 0.1 M HNO3
C- 0.1 M HNO2
D- 0.1 M H2SO4
E- 0.1 M HI
0.1 M HNO2
100
A 0.1M aqueous solution of _______ is acidic at 25oC?
A- KCl
B- Mg(OAc)2
C- CsNO3
D- NH4Cl
E- NaOCl
NH4Cl
100
Which of the following could be added to a solution of sodium acetate to produce a buffer?
A- sodium chloride or potassium acetate
B- acetic acid only
C- hydrochloric acid only
D- potassium acetate only
E- acetic acid or hydrochloric acid
acetic acid or hydrochloric acid
200
Which of the following is the weakest acid:
A- 2-hydroxybenzoic acid Ka =1.1x10-3
B- ascorbic acid Ka=1.0x10-6
C- 3-chlorobenzoic acid Ka=1.5x10-4
D- benzoic acid Ka=6.5x10-5
E- chloroacetic acid Ka =1.0x10-2
ascorbic acid Ka=1.0x10-6
200
Consider the diagram of the titration curve shown above. What type of substance was originally in the flask?
A- weak base
B- weak acid
C- strong bace
D- strong acid
strong base
200
In what order would the following compounds precipitate out if they had the same concentration?
PbSO4 (Ksp=1.8x10-18)
PbCrO4 (Ksp=1.8x10-5)
PbO (Ksp=7.3x10-22)
PbO, PbSO4, PbCrO4
200
Buffers in the human body______.
A- precipitate proteins so enzymes are inactive
B- help keep the body temperature constant
C- help change the blood plasma pH when foods are eaten
D- all of the above
E- none of the above
none of the above; help to maintain a constant blood pH
200
Acids that ionize extensively in solution are referred to as:
A- weak acids
B- lewis acids
C- bronstead-lowry acids
D- strong acids
E- Arrhenius acids
strong acids
300
Identify the acid, base, conjugate acid, and conjugate base in the following reaction:
H2O + HCO3- <-> OH- + H2CO3
Acid: H2O
Base: HCO3-
C. Acid: H2CO3
C. Base: OH-
300
Calculate the pH of a solution prepared by dissolving 0.625 mol of NH3 and 0.375 mol of NH4Cl in water sufficient to yield. 1.000L of solution. The Kb of ammonia is 1.77x10-5
Necessary equations:
Kw=1.00x10-14
pH=pKa + log [acid]/[base]
9.470
300
The solubility product, Ksp, for Ca(OH)2 is given by the expression:
A- [Ca][OH]2
B- [Ca2+][OH-]2
C- [Ca2+] x 2[OH-]
D- [Ca2+][OH-]2/[Ca(OH)2]
E- [Ca(OH)2]/[Ca2+][OH-]2
[Ca2+][OH-]2
300
BF3 is a ________.
A- Bronsted acid
B- Bronsted base
C- Lewis base
D- Lewis acid
E- Arrhenius base
Lewis acid
300
What is the pH of 1.8x10-2 M NaOH at 25oC?
12.3
400
What is the H+ concentration of a solution with a pOH of 3.45?
Necessary equations:
pH + pOH = pW
2.82x10-11
400
The Ka of HClO is 3.0x10-8 at 25oC. Calculate the pH of 0.8349 M acidic solution.
Necessary equations:
ICE chart
[H+] or [OH-] = [products][/[reactants]
3.80
400
The Ksp for Au2S is 1.0x10-39. What is the molar solubility of Au2S?
6.3x10-14
400
An aqueous solution contains 9.2x10-2 M KOH at 25oC. The pH of the solution is?
12.96
400
What is the pH of a mixture containing 0.42 M HNO2 and 0.21 M NaNO2? Ka for HNO2=4.5x10-4
Necessary equations:
pH=pKa + log[base]/[acid]
3.05
500
What is the pH of a 0.176 M ammonia (NH3) solution at 25oC? Kb (NH3) = 1.8x10-5
Necessary equations:
K = [product]/[reactant]
-log[pH]=H+
11.25
500
The pH of a 0.70M solution of a weak base is 10.2. What is the Kb for this base?
Necessary equations:
pH + pOH = 14
-log[pH]=H+
ICE chart
3.6x10-8
500
What is the molar solubility of Al3+ in a solution that is buffered at a pH of 3.00? Ksp Al(OH)3=4.0x10-15
Necessary equations:
ICE chart
Ksp=[product]/[reactant]
pH+pOH=14
4x10-18
500
A solution of KCl is added dropwise to a solution that is 0.093 M in Mg2+. When the concentration of Cl- exceeds _______M, MgCl2 will precipitate. Neglect volume changes. For MgCl2, Ksp=2.2x10-10
Necessary equations:
pH+pOH=14
Ksp=[products]/[reactants]
4.86x10-5
500
At 35oC, the equilibrium constant for the reaction below is Kc=2.5x10-8
2NOCl <-> 2NO + Cl2
An equilibrium mixtrue was found to have [Cl2]=2.0x10-3M and [NOCl]=1.2x10-4M. Calculate the concentration of NO at equilibrium.
Necessary equations:
Keq=[products]/[reactants]
3.87x10-5