pH + pOH = pKw
pKa + pKb = pKw
Ka Kb = Kw
pH = pKa + log (cb/ca)
pH= pKa + log (nb/na)
pKw = 14.00
 



1.
Which of the following arrangements has the strongest acid listed first and the weakest acid listed last?
A.
HClO4 > HClO3 > H2SO3
B.
HClO3 > H2SO3 > HClO4
C.
H2SO3 > HClO4 > HClO3
D.
HClO4 > H2SO3 > HClO3
E.
HClO3 > HClO4 > H2SO3


2.
Which of the following is the strongest acid?
A.
0.1 M HA, pKa = 4.56
B.
0.1 M HE, pKa = 2.55
C.
0.1 M HB, pKa = 5.51
D.
0.1 M HC, pKa = 6.63
E.
0.1 M HD, pKa = 7.96


3.
What is the pH of a 3.2×10–3 M Ba(OH)2 solution?
A.
11.51
B.
11.38
C.
11.81
D.
10.65
E.
13.48


4.
Select the pair of substances in which an acid is listed followed by its conjugate base.
A.
Br–, HBr
B.
NH4+, NH2–
C.
HPO42–, H2PO4–
D.
HCO3–, CO32-
E.
CO32-, HCO3-


5.
The acid ionization constant of H3PO4 is Ka = 7.2×10–3 and that of HClO is Ka = 2.9×10–8. Which statement about the equilibrium below is correct?
        H3PO4(aq)   +   ClO–(aq)   ↔   H2PO4– (aq)   +   HClO(aq)
A.
Neither reactants nor products will be favored because all of the species are weak acids or bases.
B.
Neither reactants nor products will be favored because the reaction is impossible.
C.
The initial concentrations of the reactants must be known before any prediction can be made.
D.
The reactants will be favored at equilibrium.
E.
The products will be favored at equilibrium.


6.
The organic acid RCOOH has a Ka = 6.3×10-5. What is the pH of a 0.50 M aqueous solution of this acid?
A.
2.25
B.
2.13
C.
1.90
D.
1.77
E.
1.67


7.
Hydroxylamine, HONH2, readily forms salts which are used as antioxidants in soaps. Hydroxylamine has Kb of 9.1×10-9. What is the pH of a 0.716 M HONH2 solution?
A.
10.20
B.
3.77
C.
7.00
D.
4.09
E.
9.91


8.
What is the pKa of the alkylammonium ion R3NH+? (Kb = 5.7×10–4 for R3N)
A.
11.47
B.
10.76
C.
12.50
D.
3.24
E.
2.53


9.
An aqueous solution of AlCl3 would be
A.
neutral.
B.
basic.
C.
acidic.
D.
either acidic or basic depending on the actual values of Ka and Kb which must be known.
E.
either acidic or basic depending on the amount of salt dissolved.


10.
The species Cr3+ is classified as a(n)
A.
Lewis base.
B.
Bronsted base.
C.
Arrhenius acid.
D.
Lewis acid.
E.
none of the above


11.
Which, if any, of the following aqueous mixtures would be buffer systems?
        (1) H2SO4 , NaOH              (2) H2CO3 , KHCO3
A.
2 is a buffer but 1 is not
B.
both 1 and 2 are buffers
C.
neither 1 nor 2 are buffers
D.
1 is a buffer but 2 is not
E.
none of the above


12.
Which of the following acids and its conjugate base should be used to prepare an efficient buffer with a pH = 2.3?
        (1) HClO2, Ka = 1.1×10-2
        (2) CH3COOH, Ka = 1.8×10-5
        (3) HClO, Ka = 2.9×10-8
A.
2
B.
1
C.
3
D.
both 1 and 2 would be fine
E.
both 2 and 3 would be fine


13.
What is the pH of a buffer that consists of 0.38 M HClO and 0.33 M NaClO? (Ka(HClO) = 2.9×10–8)  
A.
6.85
B.
8.88
C.
7.48
D.
5.92
E.
5.36


14.
When a strong base is titrated with a strong acid, the pH at the equivalence point is
A.
slightly basic.
B.
slightly acidic.
C.
strongly acidic.
D.
neutral.
E.
strongly basic.


15.
Which one of the following plots is the best representation of the titration curve which will be obtained in the titration of a 0.1 M weak base with a strong acid of the same concentration? In all plots, the pH of the solution is plotted versus the volume of the strong acid added.
A.
5
B.
4
C.
2
D.
1
E.
3


16.
A particular acid-base indicator has an acid ionization constant, KIn = 8.7×10–8. What would be the approximate pH range over which it changes color?
A.
6.1-8.1
B.
5.1-7.1
C.
7.1-9.1
D.
4.1-6.1
E.
3.1-5.1


17.
Calculate the molar solubility of Fe(OH)2 in pure water. (Ksp = 4.1×10–15)
A.
1.1e–4 M
B.
1.0e–5 M
C.
6.4e–8 M
D.
5.2e–4 M
E.
1.6e–5 M


18.
Calculate the molar solubility of barium sulfate, BaSO4, in 0.84 M BaCl2 solution. (Ksp = 1.1×10-10 for BaSO4)
A.
2.6e–11 M
B.
9.6e–10 M
C.
1.3e–10 M
D.
3.7e–11 M
E.
7.6e–11 M


19.
A solution is prepared by adding 0.058 mol of NaCl to 1.00 L of 0.0041 M Pb(NO3)2. Which of the following statements is correct? (Ksp = 1.7×10-5 for PbCl2)
A.
Sodium nitrate precipitates until the solution is saturated.
B.
Both sodium nitrate and lead(II) chloride precipitate.
C.
Lead(II) chloride precipitates until the solution is saturated.
D.
The solution is unsaturated and no precipitate forms.
E.
The data is not sufficient to predict precipitation.


20.
A solution is prepared by adding 2.8 mol of KCN to 1.00 L of 0.13 M Zn(NO3)2. What is the equilibrium concentration of Zn2+ ions?   (Kf = 4.2×1019 for Zn(CN)42-)
A.
1.1e–21 M
B.
1.5e–23 M
C.
3.2e–23 M
D.
6.4e–22 M
E.
1.1e–22 M


STOP This is the end of the test. When you have completed all the questions and reviewed your answers, press the button below to grade the test.