Name: _____________________
Period: ___
Acids and Bases
(1) Complete the following table.
[H+]
pH
acidic, basic, or
[OH-]
pOH
neutral?
1.5x10-2 M
5.76
11.22
3.8x10-8 M
neutral
(2) Classify the following substances as acidic or basic and determine the [H+] and [OH-].
(a) Draino, pH = 12.50
(c) Lye pOH = 2.60
(b) Vinegar pH = 2.40
(d) Cola pOH = 10.50
(3) Determine the pH and pOH of the following solutions.
(a) 0.040 M HBr
(c) 5.6x10-3 M LiOH
(b) 1.2x10-4 M HNO3
(d) 0.020 M Sr(OH)2
Answers:
(1)
[H+]
-2
pH
pOH
[OH-]
-13
acidic, basic, or
neutral?
1.5x10 M
1.82
12.18
6.6x10
M
acidic
5.8x10-9 M
8.24
5.76
1.7x10-6 M
basic
6.0x10-12 M
11.22
2.78
1.7x10-3 M
basic
2.6x10-7 M
6.58
7.42
3.8x10-8 M
acidic
1.0 x10-7 M
7.00
7.00
1.0 x10-7 M
neutral
(2)
(a) basic [H+] = 3.2x10-13 M [OH-] = 3.1x10-2 M
(c) basic [H+] = 4.0x10-12 M [OH-] = 2.5x10-3 M
(3)
(a) pH = 1.40 pOH = 12.60
(c) pH = 11.75 pOH = 2.25
(b) acidic [H+] = 4.0x10-3 M [OH-] = 2.5x10-12 M
(d) acidic [H+] = 3.1x10-4 M [OH-] = 3.2x10-11 M
(b) pH = 3.92 pOH = 10.08
(d) pH = 12.60 pOH = 1.40
Name: _____________________
Period: ___
Bronsted-Lowry Acids and Bases
(1) Write the formula for the conjugate base of the following acids.
(a) HOCl
(e) H3BO3
(b) HNO2
(f) H2PO4(c) H2SO3
(g) HSO4(d) H2CO3
(h) HC2O4(2) Write the formula for the conjugate acid of the following bases.
(e) H2PO4(a) NH3
(b) C6H5NH2
(f) SO32(c) CN(g) CO32(d) OBr
(h) BO33(3) Write a Ka or Kb expression for the following acid or base equilibria. Identify the conjugate acid-base pairs.
(a) HCN (aq) + H2O (l) U H3O+ (aq) + CN- (aq)
(b) C2H5NH2 (aq) + H2O (l)
(c) OCl- (aq) + H2O (l)
U
(d) HSO3- (aq) + H2O (l)
U
OH- (aq) + C2H5NH3+ (aq)
OH- (aq) + HOCl (aq)
U
H3O+ (aq) + SO32- (aq)
(4) Complete the following acid or base equilibria. Identify the conjugate acid-base pairs and write a Ka or Kb expression.
(a) HIO3 (aq) + H2O (l)
U
(b) C5H5N (aq) + H2O (l)
U
(c) H2C2O4 (aq) + H2O (l)
U
.
(5) Calculate the pH and pOH for the following solutions.
(a) 0.10 M HC2H3O2
(b) 0.40 M NH3
(d) HONH2 (aq) + H2O (l)
U
(e) [Cr(H2O)6]3+ (aq) + H2O (l)
(c) 0.036 HCN
(d) 0.42 M HONH2
(6) The pH of 0.250 M solution of Ascorbic Acid (HC6H7O6) is 2.35. Determine Ka.
(7) The pOH of a 0.340 M solution of Ephedrine (C10H15ON) is 2.16. Determine Kb.
(8) Determine the percent dissociation for the following compounds.
(a) 0.14 M HOCl
(b) 0.25 M C2H5NH2
(9) The percent dissociation for a 0.0150 M solution of Morphine (C17H19N) is 0.73%. Determine Kb.
(10) The percent dissociation for a 0.200 M solution of formic acid (HCO2H) is 3.0%. Determine Ka.
U
Answers:
(c) HSO3- (d) HCO3(1) (a) OCl- (b) NO2(2) (a) NH4+ (b) C6H5NH3+ (c) HCN
(d) HOBr
(3)
(a) HCN (aq) + H2O (l) U H3O+ (aq) + CN- (aq)
a
b
ca
cb
[ H 3O + ][CN − ]
Ka =
[ HCN ]
(b) C2H5NH2 (aq) + H2O (l)
b
a
U
(e) H2BO3(e) H3PO4
Ka =
U
Kb =
OH- (aq) + C2H5NH3+ (aq)
cb
ca
Kb =
H3O+ (aq) + IO3- (aq)
ca
cb
U
OH- (aq) + C5H5NH+ (aq)
cb
ca
[OH − ][C5 H 5 NH + ]
[C5 H5 N]
(7) Kb = 1.4x10-4
(8) (a) 0.050%
(9) Kb = 8.1x10-7
(10) Ka =1.9x10-4
(b) 4.8%
OH- (aq) + HOCl (aq)
cb
ca
[OH − ][ HOCl ]
[OCl − ]
U
H3O+ (aq) + SO32- (aq)
ca
cb
[ H 3O + ][ SO32− ]
[ HSO3− ]
(d) HONH2 (aq) + H2O (l) U OH- (aq) + HONH3+ (aq)
b
a
cb
ca
[OH − ][HONH 3+ ]
Kb =
[HONH 2 ]
(b) pH = 11.43 pOH = 2.57
(d) pH = 9.83 pOH = 4.17
(6) Ka = 8.2x10-5
U
(c) H2C2O4 (aq) + H2O (l) U H3O+ (aq) + HC2O4- (aq)
a
b
ca
cb
[ H 3O + ][ HC2O4 − ]
Ka =
[ H 2C2O4 ]
(e) [Cr(H2O)6]3+ (aq) + H2O (l) U H3O+ (aq) + [Cr(H2O)5(OH)]2+ (aq)
a
b
ca
cb
[ H 3O + ][[Cr ( H 2O )5 (OH )]2+ ]
Ka =
[[Cr ( H 2O )6 ]3+ ]
(5) (a) pH = 2.89 pOH = 11.11
(c) pH = 5.33 pOH = 8.67
(h) C2O42(h) HBO32-
(d) HSO3- (aq) + H2O (l)
a
b
Ka =
[ H 3O + ][ IO3− ]
[ HIO3 ]
(b) C5H5N (aq) + H2O (l)
b
a
(g) SO42(g) HCO3-
(c) OCl- (aq) + H2O (l)
b
a
[OH − ][C2 H 5 NH 3+ ]
Kb =
[C2 H 5 NH 2 ]
(4)
(a) HIO3 (aq) + H2O (l)
a
b
(f) HPO42(f) HSO3-
Name: _____________________
Period: ___
Acid Base Equilibria
(1) Determine the Kb value for the following bases.
(b) OCl(a) F-
(c) HSO3-
(2) Determine the Ka value for the following acids.
(a) HONH3+
(b) C2H5NH3+
(c) CH3NH3+
(3) (a) Rank the following substances from the strongest to weakest acid: HIO3, HF, HClO2, HCN. Explain.
(b) Rank the following substances from the strongest to weakest base: IO3-, F-, ClO2-, CN-. Explain
(4) (a) Rank the following substances from strongest to weakest base: N2H4, C2H5NH2, C5H5N, HONH2. Explain
(b) Rank the following substances from the strongest to weakest acid: N2H5+, C2H5NH3+, C5H5NH+, HONH3+. Exlain.
(5) Complete the following acid-base equilibria. Calculate an equilibrium constant for the reaction. Does the equilibrium favour the reactants
or products? Which is the stronger acid in the equilibrium? Which is the stronger base in the equilibrium?
(a) CH3NH2 (aq) + HOBr (aq)
U
(b) HONH2 (aq) + HOCl (aq)
U
(6) Determine an equilibrium constant for the following reaction: H2S (aq) + 2H2O (l)
H2S (aq) + H2O (l)
-
HS (aq) + H2O (l)
U H3O (aq) + HS (aq)
U H3O+ (aq) + S2- (aq)
+
-
U
2H3O+ (aq) + S2- (aq)
Ka1 =
Ka2 =
(7) A solution contains HSO3-. Write two equations to show that this compound is amphoteric and determine an equilibrium constant for each.
Would the solution be acidic or basic?
(8) Calculate the pH and pOH of a solution containing 0.10 M HBr and 0.10 M HOBr
(9) Calculate the pH and pOH of a solution containing 0.050 M LiOH and 0.050 M N2H4.
(10) Calculate the pH and pOH of a mixture containing 0.20 M HNO2 and 0.20 M HOCl.
(11) Calculate the pH and pOH of a mixture containing 0.15 M CH3NH2 and 0.15 M C6H5NH2.
(12) Calculate the pH and pOH of a solution containing 0.50 M HNO2 and 0.50 M NaNO2
(13) Calculate the pH and pOH of a solution containing 1.0 M CH3NH2 and 1.0 M CH3NH3Cl
(14) Determine if the following salts will be acidic, basic, or neutral. Explain.
(a) LiCl
(e) NH4IO4
(b) KCN
(f) C5H5NHClO2
(c) NH4ClO3
(g) C2H5NH3NO2
(d) CsNO2
(h) BaBr2
(15) Calculate the pH and pOH of the following salts.
(a) 0.22 M NaOCl
(d) 0.018 M HONH3Br
(b) 0.015 M CH3NH3I
(e) 0.50 M NH4OCl
(c) 0.062 M LiF
(f) 0.40 M C5H5NHOBr
Answers:
(1) (a) Kb = 1.4x10-11
(b) Kb = 2.9x10-7
(c) Kb = 6.7x10-13
(2) (a) Ka = 9.1x10-7
(b) Ka = 1.8x10-11
(c) Ka = 2.3x10-11
(3) (a) HIO3 > HClO2 > HF > HCN The larger the Ka, the stronger the acid.
(b) CN- > F- > ClO2- > IO3- The stronger the acid, the weaker the conjugate base; the weaker the acid, the stronger the conjugate base.
(4) (a) C2H5NH2 > N2H4 > HONH2 > C5H5N The larger the Kb, the stronger the base.
(b) C5H5NH+ > HONH3+ > N2H5+ > C2H5NH3+ The stronger the base, the weaker the conjugate acid; the weaker the base, the stronger the
conjugate acid.
(5) (a) K = 88
Since K>1, the equilibrium favours the products. HOBr is a stronger acid than CH3NH3+, and CH3NH2 is a stronger base than OBr-.
(b) K = 0.039
Since K<1, the equilibrium favours the reactants. HONH3+ is a stronger acid than HOCl, and OCl- is a stronger base than HONH2.
(6) K = 1.3x10-20
(7) acid: HSO3- (aq) + H2O (l)
U H3O+ (aq) + SO32- (aq)
U OH- (aq) + H2SO3 (aq)
base: HSO3- (aq) + H2O (l)
The solution would be acidic since Ka > Kb.
Ka = 1.0x10-7
Kb = 6.7x10-13
(8) pH = 1.00 and pOH = 13.00
(9) pH = 12,70 and pOH = 1.30
(10) pH = 2.05 and pOH = 11.95
(11) pH = 11.91 and pOH =2.09
(12) pH = 3.40 pOH = 10.60
(13) pH = 10.64 pOH = 3.36
(14) (a) neutral (b) basic (c) acidic (d) basic (e) acidic (f) acidic (Ka>Kb) (g) basic (Kb>Ka) (h) neutral
(15) (a) pH = 10.40 pOH = 3.60 (b) pH = 6.23 pOH = 7.77 (c) pH = 7.97 pOH = 6.03
(d) pH = 3.89 pOH = 10.11 (e) pH = 10.56 pOH = 3.44 (f) pH = 4.00 pOH = 10.00
Name: _____________________
Period: ___
Buffers
(1) Calculate the pH and pOH of the following buffer solutions.
(a) 0.40 M HNO2 and 0.40 M NaNO2
(b) 0.25 M NH3 and 0.25 M NH4I
(2) (a) Calculate the pH resulting from adding 0.010 mol of KOH to 1.0 L of the buffer in 1a.
(b) Calculate the pH resulting from adding 0.0050 mol of HCl to 100 mL of the buffer in 1a.
(c) Calculate the pH resulting from adding 0.020 mol of NaOH to 500 mL of the buffer in 1a.
(d) Calculate the pH resulting from adding 0.015 mol of HBr to 800 mL of the buffer in 1a.
(3) (a) Calculate pH resulting from adding 0.010 mol of HBr to 1.0 L of the buffer in 1b.
(b) Calculate the pH resulting from adding 0.0020 mol of NaOH to 100 mL of the buffer in 1b.
(c) Calculate pH resulting from adding 0.0080 mol of HCl to 600 mL of the buffer in 1b.
(d) Calculate the pH resulting from adding 0.020 mol of LiOH to 500 mL of the buffer in 1b.
(4) (a) Determine the pH and pOH of a buffer prepared by adding 0.50 g of sodium fluoride (NaF) to 400 mL of 0.018 M
hydrofluoric acid (HF). Assume the volume of the solution remains constant.
(b) Determine the pH and pOH of a buffer prepared by adding 4.85 g of hydrazinium chloride (N2H5Cl) to 600 mL of 0.24 M
hydrazine (N2H4). Assume the volume of the solution remains constant.
(5) Determine the mass of sodium acetate (NaC2H3O2) that must be added to 750 mL of 0.20 M acetic acid (HC2H3O2) in order
to make a buffer with pH = 4.62. Assume the volume of the solution remains constant
(6) Determine the mass of triethylammonium chloride (C6H15NHCl) that must be added to 1.0 L of 0.40 M triethylamine
(C6H14N) in order to make a buffer with pH = 10.50. Assume the volume of the solution remains constant
Answers:
(1) (a) pH = 3.40 pOH = 10.60 (b) pOH = 4.74 pH = 9.26
(2) (a) pH = 3.42 (b) pH = 3.29 (c) pH = 3.49 (d) pH = 3.36
(3) (a) pH = 9.22 (b) pH = 9.32 (c) pH = 9.21 (d) pH = 9.40
(4) (a) pH = 3.35 pOH =10.65 (b) pOH = 5.21 pH = 8.79
(5) 9.2 g NaC2H3O2 (6) 70 g C6H15NHCl
Name: _____________________
Period: ___
Titrations
(1) Give the net ionic equations the following neutralization reactions.
(a) LiOH + HCl →
(d) HF + RbOH →
(b) HNO2 + KOH →
(e) Ba(OH)2 + HI →
(c) NH3 + HBr →
(f) H2SO4 + CsOH →
(2) What volume of 0.050 M NaOH is required to titrate 50.00 mL of 0.25 M HC2H3O2?
(3) What is the concentration if 90.00 mL of NH3 requires 45.00 mL of 0.080 M HCl to titrate?
(4) Strong Base/Strong Acid
A 0.050 M solution of HCl is used to titrate 100.0 mL of a 0.050 M NaOH solution.
Determine the pH at the following intervals in the experiment. Graph the results. Label the equivalence point.
(5) 100.0 mL of HCl has been added pH =
(1) No HCl has been added pH =
(2) 25.00 mL of HCl has been added pH =
(6) 125.0 mL of HCl has been added pH =
(3) 50.00 mL of HCl has been added pH =
(7) 150.00 mL of HCl has been added pH =
(4) 75.00 mL of HCl has been added pH = 11.85
(8) 175.0 mL of HCl has been added pH = 1.85
(9) 200.0 mL of HCl has been added. pH = 1.77
pH
Strong Acid Strong Base Titration
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
25
50
75
100
125
Volume HCl added (mL)
150
175
200
(5) Strong Base/Weak Acid
A 0.100 M solution of NaOH is used to titrate 100.0 mL of a 0.100 M HC2H3O2 solution.
Determine the pH at the following intervals in the experiment. Graph the results. Label the equivalence point.
(5) 100.0 mL of NaOH has been added pH =
(1) No NaOH has been added pH =
(2) 25.00 mL of NaOH has been added pH =
(6) 125.0 mL of NaOH has been added pH =
(3) 50.00 mL of NaOH has been added pH = 4.74
(7) 150.00 mL of NaOH has been added pH = 12.30
(4) 75.00 mL of NaOH has been added pH =
(8) 175.0 mL of NaOH has been added pH =
(9) 200.0 mL of NaOH has been added. pH = 12.52
pH
Weak Acid Strong Base Titration
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
25
50
75
100
125
150
175
200
Volume NaOH added (mL)
Answers:
(1)
(a) OH- + H+ → H2O
(d) HF + OH- → F- + H2O
(b) HNO2 + OH- → NO2- + H2O
(e) OH- + H+ → H2O
(c) NH3 + H+ → NH4 +
(f) H+ + HSO4- + 2OH- → SO42- + 2H2O
(2) 0.25 L NaOH
(3) 0.040 M NH3
(4) (1) pH = 12.70 (2) pH =12.48 (3) pH = 12.23
(5) (1) pH = 2.87 (2) pH = 4.27 (4) pH = 5.23
(5) pH = 7.00 (equivalence point)
(5) pH = 8.73 (equivalence point)
(6) pH = 2.25
(6) pH = 12.04
(7) pH = 2.00
(8) pH = 12.43