CHM2045 Sample Exam #1

Name ______________________________ SS# _________________________ Section _________

Instructions: Put your name, social security number, and section number on the top of this exam page. Answer the following five (5) parts in the notation and conventions of the lecture for a total of 100 points. Read the entire exam. Work alone and consult no one, living or dead, about this test (except Brucat) until after you leave the room. Notebooks, textbooks and any other study material are not allowed in the exam room. You may use only your writing and calculating instruments; sharing of calculators is NOT allowed. Show proper units to receive credit. Your name on this exam states the assertion:
I hereby pledge that I have neither given nor received any unauthorized aid on this exam.

Q = mCDT ;         4.184 J = 1 cal ;            Specific Heat of H2O (l) = 4.18 J/K.g ;
Part I (5 points each for a total of 20 points)
a)  Express a volume of 1.00 nm3 in metric (SI) base units:

b) Write a formation reaction for Na3PO4:

c) Write down an Equation that embodies the First Law of Thermodynamics (Energy Conservation).

d) Name the compound Fe2O3:


Part II (20 points) Acetone has the molecular formula of C3H6O. (Atomic Mass H: 1.008 g/mol, Atomic Mass O: 16.000 g/mol, Atomic Mass C: 12.011 g/mol)

a) Write the balanced reaction for the complete combustion of acetone in excess oxygen.
 

b) How many grams of water are produced upon the complete combustion of 10.0 g of acetone in excess oxygen?



Part III (10 points each for a total of 20 points) Using the following Heats of Reaction
2 CO2 (g) =  2 CO(g) + O2 (g)               D Hrxno = +566.0 kJ/mol
C2H2 (g) + O2 (g) =  2 CO(g) + H2 (g)      D Hrxno = -447.7kJ/mol
2 CH4 (g) + 3 O2 (g) =  2 CO(g) + 4 H2O (l)  D Hrxno = -1214.6kJ/mol
CO2 (g) =  C(s, graphite) + O2 (g)         D Hrxno = +393.5 kJ/mol
2 H2O(l)  =  2 H2 (g) + O2 (g)              D Hrxno = +571.6 kJ/mol

a) Calculate the Heat of Formation [ in kJ/mol ] of CO (g)
 
 
 

b) Calculate the Enthalpy change [ in kJ/mol ] for the reaction:
2 C2H2 (g) + 5 O2 (g) = 4 CO2 (g) + 2 H2O (l)
                                                                                             D Hrxn o = __________ kJ/mol
 
 


Part IV (20 points) Consider a thermally insulated, constant pressure calorimeter that has a heat bath that consists of 500 mL of water. 1.25 mole of a fuel is burned with excess oxygen in this calorimeter and the temperature rise of the heat bath is 50.0 oC. What is the molar Heat of Combustion [ in kJ/mol ] of the material?
 
 
 
 


Part V (20 points) If 27.5 g of N2 gas are reacted with 10.0 g of H2 gas, and the reaction proceeds as far as is possible, how many grams of ammonia are produced? (Atomic Mass H: 1.008 g/mol, Atomic Mass O: 16.000 g/mol, Atomic Mass N: 14.007 g/mol)