Acids and Bases Review
1.
What 2 ions are formed when water ionizes?
H+ (attaches to another water molecule to become H3O+)= hydrogen ion (hydronium ion)
OH- = hydroxide ion
2.
Write the equilibrium equation and expression for the ionization of water. Include the value for Kw.
2H2O ↔ H3O+ + OHKw = [H3O+][OH-]
3.
Kw = 1.0 x 10-14
State the Arrhenius definition of an acid and base. Provide an example of each.
An acid is a substance that dissociates into an H+ and an anion in aqueous solutions. A base is a substance that
dissociates into an OH- and a cation in aqueous solutions. An example of an acid is HCl. An example of a base is
NaOH.
4.
State the Brønsted-Lowry definition of an acid and base. Provide an example of each.
An acid is a substance that donates a proton. A base accepts a proton. An example of an acid is HCl. An example of a
base is NH3.
5.
For each of the following equations, label the acid, base, conjugate acid, and conjugate base.
A
B
CB CA
a. HF + H2O  F- + H3O+
B
A
CA
CB
+
b. NH3 + HCl  NH4 + ClB
A
CA
CB
+
c. H2O + H2O  H3O + OHA
B
CB
CA
d. H2S + H2O  HS- + H3O+
A
B
CB
CA
e. HClO4 + H2O  ClO4- + H3O+
A
B
CA
CB
f. H2O + NH3  NH4+ + OHB
A
CA
CB
g. CO3- + H2O  HCO3- + OHB
A
CA
CB
h. CH3COO + HCl  CH3COOH + ClB
A
CB
CA
i.
H2O + HNO3  NO3 + H3O+
6.
What is the conjugate base of these Brønsted-Lowry acids?
a. H2SO4
HSO4-
b. HBr
Br-
c. NH4+
NH3
d. H2O
OH-
e. HPO4-2
PO4-3
7.
Write a chemical equation that shows why the problem of excess stomach acid, HCl, can be partially relieved by milk
of magnesia, which contains Mg(OH)2.
2 HCl + Mg(OH)2 → MgCl2 + 2 H2O
8.
The concentration of a solution of potassium hydroxide is determined by titration with nitric acid. A 70.0 mL sample
of KOH is neutralized by 23.5 mL of 0.75 M HNO3. What is the concentration of the potassium hydroxide solution?
HNO3 + KOH → KNO3 + H2O
Va Ma = VbMb
Va = 23.5 mL
Ma = 0.75 M
Vb = 70.0 mL
23.5 mL (0.75) = 70.0 mL (Mb)
9.
Mb = ?
Mb = 0.25 M KOH
What volume of 0.35 M NaOH is required to neutralize 50.0 mL of 0.25 M HCl.
HCl + NaOH → NaCl + H2O
Va Ma = VbMb
Va = 50.0 mL
Ma = 0.25 M
Vb = ?
Mb = 0.35 M
50.0 mL (0.25 M) = Vb (0.35 M)
Vb = 36 mL NaOH
10. Which solution has the lower pH value: 0.1 M HNO3 or 0.001 M HNO3?
0.1 M HNO3 (1 vs 3)
11. For each of the following, determine the [H3O+], [OH-], pH, pOH, and whether the solution is acidic, basic, or neutral.
a. 0.10 M HCl
[H3O+]= 1.0 x 10-1
[OH-]= 1.0 x 10-13
pH= 1.0
pOH= 13
acid
b. 0.0010 M HCl
[H3O+]= 1.0 x 10-3
[OH-]= 1.0 x 10-11
pH= 3.0
pOH= 11
acid
c. 0.00010 M HCl
[H3O+]= 1.0 x 10-4
[OH-]= 1.0 x 10-10
pH= 4.0
pOH= 10.
d. 0.50 M HCl
[H3O+]= 5.0 x 10-1
[OH-]= 2.0 x 10-14
pH= 0.30
pOH= 14
acid
e. 0.0025 M NaOH
[H3O+]= 4.0 x 10-12 [OH-]= 2.5 x 10-3
pOH= 2.6
base
f.
[H3O+]= 6.33 x 10-11
[OH-]= 1.58 x 10-4
pH= 10.2
pOH= 3.80
base
g. pH = 2.26
[H3O+]= 5.50 x 10-3
[OH-]= 1.82 x 10-12
pH= 2.26
pOH= 11.7
acid
h. pOH= 7.69
[H3O+]= 4.90 x 10-7
[OH-]= 2.00 x 10-8
i.
pOH = 1.00
[H3O+]= 1.00 x 10-13
[OH-]= 1.00 x 10-1
pH= 13.0
pOH= 1.00
j.
pH = 5.04
[H3O+]= 9.12 x 10-6
[OH-]= 1.00 x 10-9
pH= 5.04
pOH= 8.96
acid
k. pH = 7.00
[H3O+]= 1.00 x 10-7
[OH-]= 1.00 x 10-7
pH= 7.00
pOH= 7.00
neutral
l.
[H3O+]= 6.31 x 10-14 [OH-]= 1.58 x 10-1
pH= 13.2
pOH= 0.80
base
0.000158 M NaOH
pH = 13.2
pH= 11
pH= 6.31
pOH= 7.69
acid
acid
base
12. What is the range of the pH scale?
0-14
13. Finish the neutralization reaction:
HBr + NaOH → H2O + NaBr
14. What is a chemical indicator?
Chemical that changes color in the presence of solutions with different pH’s.
For each of the following fill in the missing blanks.
Name
Formula
15. Nitric acid
__HNO3____
16. _hydrochloric acid_____
HCl
17. _iodic acid___________
HIO3
18. Sulfurous acid
__H2SO3_____
19. Hydrobromic acid
__HBr________