Science 30 Acid/Base Chemistry Review
1) Using the Bronsted Lowry definition, identify all acids and bases (including
conjugate
acids and bases) in the following chemical reactions. Use A, B, CA, CB for your
labels.
H3O+ + HSO4-
a. H2O + H2SO4
b. OH- + HCl
Cl- + H2O
c. HCl + H2O
Cl- +
H3O+
CH3COO- + NH4+
d. CH3COOH + NH3
2) Here is a list of dissociation equations:
i)
Na2SO4 (s)  2 Na+ (aq) +
ii) KHCO3 (s)  K+ (aq) +
iii) Mg(OH)2 (s)
iv) CaO (s)
v)
SO42- (aq)
HCO3- (aq)
Mg2+ (aq)
Ca2+ (aq) +
+
2 OH-
(aq)
O2- (aq)
H2SO4 (g)  2 H+ (aq) +
SO42-
(aq)
Choose which of the above dissociation equations best represents:
a) an Arrhenius acid? EXPLAIN.
b) an Arrhenius base? EXPLAIN.
3)
What is the [H3O+(aq)] of a sample of HBr(aq) if its pH is 2.31?
4) What is the conjugate acid for each of the following:
a) HSO4b) H2O
5) What is the conjugate base for each of the following:
a) HSO4b) H2O
6) There are two unlabeled bottles in the lab. One contains hydrofluoric acid and
the other contains hydrochloric acid. You run a conductivity test on each
unknown solution. Solution A is a poor conductor of electricity. Solution B is a
very good conductor of electricity. Match the identity of each unknown solution.
Explain your answers.
7) Complete the following table
[ H3O+ ]
pH
Acidic, Basic or
Neutral ?
6.03 x 10-8 mol/L
5.5688
1.00 x 10-11 mol/L
13.11
5.0456 x 10-7 mol/L
12.21
4.110
8) If carbonic acid is produced from a reaction of CO2 (g) with water what is the
[ H3O+ ], in a sample of rainwater with a pH of 4.0 ?
Indicators and pH:
To accurately determine the pH of a solution, more than one indicator must be used.
Using the colours and the table, give a range for the unknown pH.
Eg.
9) A solution was tested with the following indicators. What is its pH?
Indicator
Bromothymol blue
Phenolpthalein
Phenol red
Eg.
10) A solution was tested with the following indicators. What is its pH and
[H3O+(aq)]?
Indicator
Orange IV
Methyl violet
Bromocresol green
Methyl Orange
Eg.
Colour
blue
colourless
red
Colour
yellow
blue
yellow
red
11) A sample of rainwater was tested with the following indicators. What is its
pH and [H3O+(aq)] ? Does this sample make one suspicious that acidic deposition
is occurring in the area?
Indicator
Thymol blue
Methyl orange
Bromocresol Green
Bromothymol Blue
Colour
yellow
yellow
blue
yellow
12) 10.00 mL samples of 1.332 mol/L lithium hydroxide were titrated with solutions of
ethanoic acid. The following results were obtained. Calculate the concentration of the
acid.
Initial burette reading (mL)
Trial 1
50.0
Trial 2
50.0
Trial 3
38.1
Trial 4
26.1
Final burette reading (mL)
35.6
38.1
26.1
14.0
Volume of acid added (mL)
13) 25.00 mL samples of 0.115 mol/L HBr(aq) were titrated with a solution of LiOH(aq). The
following results were obtained. Calculate the concentration of the base.
Initial burette reading (mL)
Trial 1
0.200
Trial 2
9.900
Trial 3
17.60
Trial 4
25.30
Final burette reading (mL)
9.900
17.60
25.30
32.90
Volume of acid added (mL)
14)
A.
B.
C.
D.
The two main contributors to the formation of acid rain are:
methane and ozone
ozone and nitrogen oxides
sulphur oxides and methane
nitrogen oxides and sulphur oxides
15) What acids are formed when these gases react with water?
16) The combustion of coal is likely one source of the pollutant
A. Hg(l)
B. Pb(s)
C. SO3(g)
D. ClO(g)
17) The largest source of nitrogen dioxide in urban areas is
A, combustion of ammonia
B. internal combustion engines
C. decomposition of organic matter
D. effluent released from water treatment plants.
18) Sulphur dioxide emissions from a coal-fired plant could be reduced by
A. installing a scrubber
B. installing a catalytic converter
C. burning a lower grade of coal
D. carrying out combustion at a lower temperature
19) Alberta has less of a problem with acid rain than Eastern Canada. Explain why this is so
in terms of industry, soil, and weather conditions.
20) The body tissues of certain fish, such as brook trout, can tolerate a relatively low pH.
Explain how they might be affected indirectly by acidic deposition?
21) Scientists found that vegetation at high altitudes is affected more severely by acidforming gases in the atmosphere than vegetation at lower altitudes. This might be
accounted for by the fact that:
A. the vegetation is less tolerant to acidic gases
B. cold conditions increase the pH of the dissolved gases
C. the moisture in the lower parts of the clouds is more acidic
D. high altitude plants have lower metabolic rates.
22) Why is normal rainwater slightly acidic (pH = 5.5)?