Canadian
International
Matriculation
Programme
[SCH4U] CHEMISTRY FINAL EXAMINATION
Date:
Wednesday, May 30, 2012
Time:
8:30 p.m. – 10:30 p.m.
Length:
2 Hours
Teachers:
Ms Kimberley Gagnon and Dr. Deoraj Narine
Circle your teachers name above:
Student Name: ________________________Section/Period: _______
INSTRUCTIONS TO STUDENTS:
1. Check that your examination has 15 typed pages, including the cover page.
2. Answer all questions in the spaces provided.
3. Marks are indicated in the right-hand margin in brackets.
4. You may use a scientific calculator.
5. Chemistry Tables are provided on pages 12 to 15. Please tear them off now for easier
referral.
6. There are four sections to the exam. Read instructions to each part carefully.
STRUCTURE/EVALUATION
PART A Knowledge/Understanding
PART B Communication
PART C Thinking/Investigation
PART D Application
TOTAL
For office use only:
Part A
Part B
Part C
25 marks, allow 25 minutes
20 marks, allow 25 minutes
40 marks, allow 50 minutes
15 marks, allow 20 minutes
100 marks, 2 hours
Part D
Total
Page 2 of 10
Part A: Knowledge/Understanding: (25 marks, allow 25 minutes)
Multiple Choice: On the line to the left of the question, identify the letter of the choice that best completes the
statement, or answers the question.
Part B: Communication: (20 marks, allow 25 minutes)
For the following questions, write the most appropriate answer in the space provided.
1. Explain Hund’s rule and the Pauli exclusion principle. Give an example to show how these two rules
are used. (4 marks)
Page 3 of 10
2. What does VSEPR stand for? How is this theory used to predict molecular shape? (2 marks)
3. Write the thermochemical equation for the formation of calcium carbonate. The standard molar
enthalpy of formation of calcium carbonate is 1207 kJ/mol. (2 marks)
4. What are the two major requirements for a reaction to occur? (2 marks)
5. The equilibrium constant for the following reaction is 4.8  103 at 25ºC. (3 marks)
N2O4(g)  2NO2(g)
a) Which direction does the equilibrium normally favour?
_______________________
b) Which species has the greater concentration?
_______________________
c) What is the equilibrium constant for the reverse reaction?
_______________________
6. List three different strategies that could be used to shift the following equilibrium toward the products.
(3 marks)
2NOCl(g)  2NO(g)  Cl2(g)
Page 4 of 10
7. Use the concept of equilibrium to explain the difference between a weak acid and a strong acid. (2
marks)
8. Determine whether the following reaction is a redox reaction. Explain your answer. (2 marks)
MnO4 + CN  MnO2 + CNO






Part C: Thinking/Investigation: (40 marks, allow 50 minutes)
Answer eight (8) of the following questions ONLY. If you attempt more than eight questions
CIRCLE the questions you want marked otherwise the first eight will be marked.
For the following questions, write the answer in the space provided. Use complete sentences in your
answer. If the question requires mathematical calculations, show all of your work. Write a final statement
that gives your solution. Answer all questions with the correct number of significant figures (digits).
1. For each molecule, draw the Lewis structure, use the VSEPR theory to predict the shape of the
compound, decide whether or not the molecule is polar, and draw the dipole movement for the
molecule if the molecule is polar (5 marks)
+
a) NH4
b) AsCl5
Page 5 of 10
2. Complete the following table.
Reaction
(5 marks)
Draw and name organic product(s) produced
3,4-dimethyl-2-pentene + bromine 
2-methylbutanal + K2Cr2O7 (alkaline)
2
4 ( aq)


3-ethyl-3-octene + H20 (l) 
H SO
2,4-dibromopentanoic acid + ammonia
Heat


4-methylhexanol
/ 1800 C
2
4 ( aq)




H SO
3. Use the following diagram to answer the questions below.
(5 marks)
a) Is the reaction exothermic or endothermic? Explain.
b) What letter represents the activation energy of the forward reaction?
c) What letter represents the heat of reaction?
d) What letter represents the activation energy of the reverse reaction?
________
________
________
Page 6 of 10
4. Use standard heats of formation to calculate the heat of reaction for the following equation.
(5 marks)
2H2S(g)  3O2(g)  2H2O(l)  2SO2(g)
5. The experimental data in the table below were collected for the following reaction of nitrogen
monoxide and hydrogen. What is the rate law for this reaction (include the value for the rate constant)?
(5 marks)
2NO(g)  2H2(g)  N2(g)  2H2O(g)
Trial
1
2
3
Initial concentration (mol/L)
[NO]
[H2]
0.10
0.10
0.10
0.20
0.20
0.10
Initial rate of disappearance of NO (mol/Ls)
1.23  103
2.46  103
4.92  103
Page 7 of 10
6. Complete the following table, based on the following equilibrium system.
Ni2(aq)  6NH3(aq)  Ni(NH3)62(aq)
green
(5 marks)
blue
Stress
addition of nickel(II) nitrate
removal of ammonia
addition of water
addition of inert gas at constant pressure
removal of Ni(NH3)62(aq)
Colour
7. a) Draw a graph to show the changes in [HI], [H2], and [I2] in the following equilibrium system, if the
container initially contains 2.0 mol/L HI(g).
(3 marks)
H2(g)  I2(g)  2HI(g)
b) Continue the graph above to show the change in equilibrium if the concentration of HI is increased.
(2 marks)
8.
Balance only ONE of the questions below.
FeSO4 + H2SO4 +
KMnO4  Fe2(SO4)3 +
NO3 + Bi  Bi3+ + NO2
(acidic)
(5 marks)
K2SO4 + MnSO4 + H2O
Page 8 of 10
9.
0.566 mol of NO2(g) is placed in a 1.00 L container. After the following equilibrium is established, the
container is found to contain 0.500 mol of NO. What is the equilibrium constant for this reaction?
(5 marks)
2NO2(g) 
2NO(g) 
O2(g)
10. An ammonia solution has an initial concentration of 0.075 mol/L. What is the pH of this base solution?
(5 marks)
Page 9 of 10
Part D: Application: (15 marks, allow 20 minutes) Note: Each question is worth 7.5 marks.
Answer two (2) of the following questions ONLY. For the following questions, write the answer in the space
provided on pages 14 and 15. Use complete sentences in your answer. If the question requires mathematical
calculations, show all of your work. Write a final statement that gives your solution.
1. Ammonium nitrate is used in a cold pack.
NH4NO3(s)  NH4(aq) + NO3(aq) H  26.2 kJ
a) The cold pack contains 30.0 g of ammonium nitrate and 100.0 mL of water. What is the
temperature change of the water, assuming that all the heat absorbed by the reaction comes
from the water? Note: The specific heat capacity of water is 4.184 J/(gC).
b) If the initial temperature of the water is 22.0C, what is final temperature of the water?
c) Why is it important to make sure that the correct amount of the ammonium nitrate is used in
the cold pack when placing the cold pack on an injury?
2. Arian decided to make some orange juice by adding a bit of orange syrup to a glass of water and then
stirred his drink with a spoon made of magnesium.
a) Explain what would happen to his spoon and the solution.
b) What happens in terms of the half-reactions, overall reaction, and cell potential involved.
3. a) Design an experiment that would allow you to distinguish between 2-butanol (sec-butanol) and 2methyl-2-butanol (t-butanol). List the steps or draw a flowchart. Include all apparatus, reagents, and
quantities.
b) Explain what you would expect to observe during the experiment, to allow you to distinguish
between these two compounds. You may draw a table of observations.
c) Write a short conclusion.
4. Citric acid, C6H8O7 (abbreviated H3Ct), is present in citrus fruits such as oranges, lemon, and
grapefruits. It is an important chemical in the food industry, for adding favour and preventing the
growth of bacteria. If the concentration of citric acid in a juice is 0.011 mol/L, what is the pH of the
juice?
H3Ct  H2O  H3O+  H2Ct
H2Ct  H2O  H3O+  HCt2
HCt2  H2O  H3O+  Ct3
Ka  7.1  104
Ka  1.7  105
Ka  6.4  106
Note: Answer TWO of the questions above on the next two pages.
Page 10 of 10
Answer to question ______.
Answer to question ______.