1. Page 1 of 6
SCHOOL OF CHEMICAL, BIOLOGICAL, AND ENVIRONMENTAL ENGINEERING
OREGON STATE UNIVERSITY
CHE 299: MATERIAL & ENERGY BALANCES SUMMER, 2014
WEEK 9 TEST DUE DATE: MONDAY, AUGUST 25, 10 AM PACIFIC TIME
Test Instructions
1) There are 2 options for completing Test #9.
Option 1: Download the pdf or word document of “Test #9” onto your computer and
print it out. Complete the exam using a pen or pencil. Then scan the completed exam to
your computer and upload into blackboard.
Option 2: Download the word document of “Test #9” onto your computer and complete
the exam using Microsoft Word text and Microsoft Word Equation Editor. Re-save the
Test and upload it into blackboard.
****IMPORTANT*****
For both options, re-save your Test with the following file name as a pdf.
CHE 299_Test 9_Your Last Name-Your First Name.pdf
For example, if I were turning in the test, the file name would be the following,
CHE 299_Test 9_Oleksak-Richard.pdf
If your exam is not named according to this system, I will subtract 5 points from your
Test Score.
2) Your name must be on EVERY page of the Test. If your name is not on every page of
the Test, I will subtract 5 points from your Test Score.
3) SHOW ALL WORK, including unit conversions. No work = no credit on the exams.
Show all of the steps in your solution! Complete the solution in the space provided
below the problem statement.
4) This test must be completed ALONE. Please print your name and sign and date on the
line below which is an agreement that you did not give or receive any written, verbal or
electronic help or assistance on this test. Cheating is not tolerated and if you cheat, you
will be automatically given a grade of 0% on the test. Your signature can be scanned.
Printed Name Signature Date

2. NAME: CHE 299, Summer 14 Exam #9
Page 2 of 6
1. (______/10 Points) Phase Changes
(Circle or highlight the correct awnsers)
Which of the following changes of phase is exothermic?
a) Gas to Liquid c) Solid to Gas
b) Solid to Liquid d) Liquid to Gas
2. (______/10 Points) Exothermic Reactions
(Circle or highlight the correct awnsers)
Exothermic reactions are usually self-sustaining because
a) Exothermic reactions usually require low activation energies
b) Exothermic reactions usually require high activation energies
c) The energy released is sufficient to maintain the reaction
d) The products contain more potential energy than the reactants

3. NAME: CHE 299, Summer 14 Exam #9
Page 3 of 6
3. (______/20 Points) Conversion of FeS2
(Remember to show all steps in your work)
In the reaction
4FeS2(s) + 11O2(g) → 2Fe2O3(s) + 8SO2(g)
the conversion of FeS2(s) to Fe2O3(s) is only 80% complete. If the standard heat of reaction for
the reaction is calculated to be -567.4 kJ/g mol FeS2(s), what value of ΔH°rxn will you use per kg
of FeS2 burned in an energy balance?

4. NAME: CHE 299, Summer 14 Exam #9
Page 4 of 6
4. (______/20 Points) Hexafluorosilicic acid Formation
(Remember to show all steps in your work)
Hexafluorosilicic acid is made by the reaction of silica and hydrofluoric acid by the following
reaction
6HF + SiO2 → H2SiF6 + 2H2O ΔHr = -670 kJ/mol
What is the enthalpy change if the feed into a reactor contains 3 mol HF and 1.5 mol SiO2?

5. NAME: CHE 299, Summer 14 Exam #9
Page 5 of 6
5. (______/20 Points) Enthalpy
(Remember to show all steps in your work)
Consider these reactions, where M represents a generic metal.
1. 2M(s) + 6HCl(aq) → 2MCl3(aq) + 3H2(g) ΔH1 = -881.0 kJ
2. HCl(g) → HCl(aq) ΔH2 = -74.8 kJ
3. H2(g) + Cl2(g) → 2HCl(g) ΔH3 = -1845.0 kJ
4. MCl3(s) → MCl3(aq) ΔH4 = -316.0 kJ
Use the information above to determine the enthalpy of the following reaction
2M(s) + 3Cl2(g) → 2MCl3(s) ΔH = __________ kJ

6. NAME: CHE 299, Summer 14 Exam #9
Page 6 of 6
6. (______/20 Points) Exothermic Reactions
(Remember to show all steps in your work)
Circle which of the following reactions are exothermic
A. 2Mg(s) + O2(g) → 2MgO(s) ΔH = -1203 kJ/mol
B. NH3(g) + HCl(g) → NH4Cl(s) ΔH = -176 kJ/mol
C. AgCl(s) → Ag+
(aq) + Cl-
(aq) ΔH = 127 kJ/mol
D. 2Fe2O3(s) + 3C(s) → 4Fe(s) + 3CO2(g) ΔH = 468 kJ/mol
E. C(graphite) + O2(g) → CO2(g) ΔH = -393.5 kJ/mol
F. CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) ΔH = -891 kJ/mol