Name ___________________________
CHEM 107
Spring 2017
Common Graded Assignment
(50 points)
Introduction:
While the majority component of air is nitrogen (N2), the gas is very unreactive because
of its stability due to the triple bonds that hold the nitrogen atoms together. Nitrogen
gas is, therefore, relatively unavailable for chemical reactions. One of the few ways to
“fix” nitrogen, making a nitrogen compound from the elemental nitrogen in the
atmosphere, is the Haber process (aka Haber-Bosch process). In this reaction, nitrogen
gas combines with hydrogen gas to yield ammonia. The enthalpy (ΔH) of this reaction is
-92.22 kJ.
This process was discovered by the German chemist Fritz Haber in the early twentieth
century. Through extensive experimentation, Haber found the conditions that would
produce adequate yields (at a temperature of about 500oC and a pressure of about 200
atm). This process holds a significant importance today because of its application in the
industrial production of ammonia-based fertilizer. In 1918, Haber received the Nobel
Prize in Chemistry for work. However, a lot of controversy followed the Nobel Prize
award.
For this experiment, 19.25 grams of nitrogen gas and 11.35 grams of hydrogen gas are
allowed to react in the reaction vessel. The ammonia vapor that is produced is then
condensed, liquefied, and collected into a collection vessel.
Name ___________________________
QUESTION SHEET
Students must work individually. The following questions refer to the reaction
described on the previously attached page. Answer the questions on the Answer Sheet
provided. Make sure to put your name on each page. ANY ANSWERS THAT ARE NOT
WRITTEN ON THE ANSWER SHEET WILL NOT BE GRADED. MAKE SURE TO TURN IN
BOTH THE QUESTION SHEET AND THE ANSWER SHEET.
You must show all relevant work clearly and completely. Appropriate use of
significant figures and units is required in order to receive full credit.
1. Is the Haber process an exothermic or endothermic reaction? (2 pts)
2. Write a balanced thermochemical equation with phase labels for the Haber
process with the heat energy as part of the equation. (3 pts)
3. What is the theoretical yield of ammonia (in grams) if 19.25 grams of nitrogen
gas and 11.35 grams of hydrogen gas are allowed to react? (11 pts)
4. Based on your theoretical yield, what is the percent yield of ammonia if only 8.93
grams of ammonia is produced? (5 pts)
5. How much heat energy (in kJ) will be absorbed or released if 8.93 grams of
ammonia is produced? State whether the energy will be absorbed or released.
(7 pts)
6. Compare and contrast the positive and negative effects that result from the use
of the Haber process. Discuss the controversy that followed the awarding of the
Nobel Prize in Chemistry to Haber. Based on this discussion, do you think Haber
should have been awarded this prestigious award for his work? Explain. (22 pts)
ASSIGNMENT SPECIFICATIONS:
Your answer to #6 should:
be typed, doubled-spaced in Times New Roman with a font size of 12;
no more than one (1) page in length (excluding the reference page);
be written in APA style (http://library.ccbcmd.edu/screens/web/apa.pdf) with
appropriate reference page;
be submitted as a hard copy with the rest of this assignment;
**an additional electronic submission (i.e. through SafeAssignment in
Blackboard) may be required by your instructor**;
utilize at least two (2) credible, appropriate sources of information (Wikipedia
and other general on-line encyclopedias are not considered acceptable sources
Name ___________________________
while subject-specific encyclopedias provided in the CCBC reference database
are acceptable.)
GRADING:
This assignment will account for a minimum of 5% of the total course grade.
SUBMISSION GUIDELINES:
ANSWER SHEET
Must show work for #3 through #5 in order to receive full credit for the answers to
those questions. Appropriate use of significant figures and units is required in order
to receive full credit.
1. Answer _____________________________________
2. Answer ___________________________________________________________
3. Show calculations (use dimensional analysis):
Answer _____________________________________
Name ___________________________
4. Show calculations:
Answer _____________________________________
5. Show calculations (use dimensional analysis):
Answer _____________________________________
6. Provide your answer to question #6 on (a) separate sheet(s) of paper.